AEC Solutions / Mixed-Use Buildings

Supplemental Narrative for NZEB: Cost Analysis and Cost Modeling

November 5, 2010
KEYWORDS DOE / Net Zero Energy / NREL
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Co-Moderator: Bruce McLean Haxton, AIA, LEED AP, Sustainable Consulting Architect with over 30 years experience.  He authored more than 40 articles and research papers and has spoken at world conferences on sustainable facilities, laboratories, and science parks.

Co-Moderator: Michelle Hucal LEED AP is senior editor of ED+C and Sustainable Facility.  She has led numerous conferences on sustainable design and is a former board member of the USGBC.


John Andary, Principal with Stantec in San Francisco.  John’s team provided Sustainable Design Consulting and MEP Engineering on the NREL’s RSF, and Marin Country Day School projects. Stantec’s Vancouver office provided these services for the Dockside Green project.

Tim Babb, CCC, Senior Project Manager with Project Time & Cost, Inc. an international project management and cost engineering firm providing cost estimating and cost control.  He has 27 years experience in construction management, cost estimating, and scheduling.

Jeff Baker is the Director of Laboratory Operations at The Office of Energy Efficiency and Renewable Energy, National Renewal Energy Laboratory (NREL). He has worked on the Research Support Facility (RSF) since 1995.

Michael Bendewald is an analyst at Rocky Mountain Institute (RMI). His recent focus is with developing educational material, providing lifecycle cost analysis for building retrofits, and developing a carbon-analysis tool.

Rick Cantwell, PE, President / CEO, Odell International, LLC, Huntersville, NC.  Odell International is a leading Program and Technology Management firm. He has over 30 years experience in program management and design-build expertise worldwide.

Dimitri Contoyannis, PE manages IES’s San Francisco consulting team Specializing in advanced energy and building performance simulation. He is responsible for specifying features in IES’s VE software platform for the North American market.

Russ Drinker, AIA LEED AP is the Managing Principal of the San Francisco Office for Perkins & Will. He leads numerous design teams for sustainable design projects and technology campuses in the USA and internationally.

Andy Fieber, LEED AP BD&C, Project Manager and LEED Specialist for The Boldt Company with building expertise in higher education, healthcare, and research facilities. He was a project team member on the net zero energy LEED Platinum Aldo Leopold Center.

Joel Krueger is a senior project manager and a green building specialist with the Kubala Washatko Architects (TKWA) in Cedarburg, Wisconsin. He was the project manager for the Aldo Leopold Legacy Center project.  He has worked on high-performance buildings with TKWA.

Tom Kubala is a principal and the co-founder of The Kubala Washatko Architects, Inc., Cedarburg, Wis.  TKWA led the design team for the Aldo Leopold Legacy Center in Baraboo, Wis., a LEED Platinum, net-zero energy, and carbon-neutral facility.

Zaki Mallasi, PhD, MSc, LEED BD+C is an Architectural BIM Specialist with Perkins + Will, primarily working on Healthcare and K-12 projects. He is at the front-end of BIM implementation and R&D in projects and analyzing building energy performance.  

Philip Macey, AIA, LEED AP Director of Energy and Sustainability and the design-build project manager for Haselden Construction.  Macey was formerly at RNL Architects providing project management on the RSF project during the competition and design phase.

Tavis McAuley, LEED AP is an Intern Architect and cost analyst with Perkins + Will. He has written a book and several papers examining in detail the cost implications and advantages of sustainable design.

Shanti Pless, Commercial Buildings Research Engineer at NREL, Golden, Colorado, with a focus on applied research and design processes for high performance commercial buildings.

Ken Powelson, LEED AP was Project Architect for EHDD Architects, San Francisco on the Marin Country Day School, a net zero energy building.

Jason Pratt, Jason Pratt is a Sr. Subject Matter Expert at Autodesk, helping owners and project teams implement and use BIM. Jason designed and built (and lives in) one of the first homes to earn a 5-star rating in the Green Building Program in Austin, TX.

Scott Shell is a principal at EHDD Architecture. EHDD has completed five net-zero energy buildings and is beginning construction on two more: The David and Lucile Packard Foundation’s office and the 200,000-square-foot Exploratorium.

Andy Smith, AIA is a Solutions Executive with Bentley Systems, Inc.  Andy’s work focuses on assisting AEC firms and building owners to apply design and simulation software to improve project delivery processes and deliver high performance buildings.

Paul Torcellini is Principal Group Manager for Commercial Buildings Research at the National Renewable Energy Laboratory (NREL). He also served on the integrated project team which represented the owner for the NREL Research Support Facility, Golden, Colorado.

Gregg Tucek is a Project Manager for The Boldt Company with twenty years of building experience in higher education, healthcare and research facilities. His experience with net zero energy projects includes the LEED Platinum Leopold Legacy Center.

Dana Villeneuve is a LEED Project Manager with Architectural Energy Corp. AEC served as the Sustainable Design Consultant for the NREL Research Support Facilities, providing LEED, Daylighting, Commissioning, and M&V services on the project.

NZEB EXPERT ROUNDTABLE III: Cost Analysis and Cost Modeling

A condensed version of this roundtable appeared in the October issue of ED+C and can also be found online with graphics and illustrations provided by the participants at:

Sustainable Architect, Bruce Haxton and ED+C senior editor Michelle Hucal, organized the NZEB Expert Roundtable III: Cost Analysis and Cost Modeling teleconference to investigate some of the NZEB cost issues uncovered in the first and second NZEB Roundtable conference of May and July 2010.  This session is focused on Net Zero Energy Building costs analysis and cost models for different building types. The expert team tried to answer questions: What are the extra costs and potential savings for NZEB facilities?  What new paradigm is created in designing a NZEB from a cost analysis perspective?  Do LEED line items really have a place in NZEB costing or should we be looking at “Energy Saving Parameters” besides LEED parameters? What are the LEED line item costs and how do they fit into energy savings, user well being, and savings?  What are the “rules of thumb” and “metrics” to be used in developing NZEB buildings and campuses?  What are the NZEB costs, savings, and performance resources that would help the design professionals design NZEB buildings? What are the “building type cost models” for different building types that would help NZEB professionals in their work? What would the ED+C readership use to further investigate cost analysis for Net Zero Energy Buildings?

Russ Drinker from Perkins + Will, San Francisco hosted the teleconference to bring this information to the Environmental Design + Construction readership.  The teleconference focused on architects, engineers, software consultants, consultants, contractors, owners, and users.

The teams that supplied the most information for the study were Perkins + Will Architects, The Kubala Washatko Architects Team, EHDD Team and  RNL /Haselden/Stantec/AEC Team for the NREL Research Support Facility. 

The software manufacturers Autodesk, Bentley Systems, and IES, all shared their expertise regarding their respective software systems and the interface with NZEB cost analysis.  NREL has expertise in software systems because of the renewable energy research they perform.  They shared their expertise during the NZEB teleconference.

The teleconference was transcribed and listed in part here. The following are excerpts from the teleconference that best illustrate important information on NZEB cost analysis and cost modeling. The conferees hope that the article, total narrative online, resource sections, building type cost models (see PDFs at the end of this article), and the article conclusions will help the ED+C readership in their work to design future Net Zero Energy Buildings.


Bruce Haxton (Co-Moderator): I believe our teleconference team can develop the cost information, not only from both an analysis perspective and also from a perspective of building cost and performance models that professionals, students and consultants can use to help design better, more cost effective net zero energy buildings. The first information will deal with design features, design process, energy performance and cost analyses using Whole Building Approach. The second analysis will focus on LEED line items and what the NZEB designers have experienced on their projects. A third analysis is a look at performance and cost parameters.  At the end of the article we will touch on the cost of oil and other life cycle cost analysis in the future and the potential impact on NZEB facilities. The analysis and building models we will analyze will be: housing / commercial, school, small office, and large office model. 

Whole Building Design Approach / Performance Analysis / Cost Analysis / Cost and Performance Models

Bruce Haxton: With the integration of many different building systems within the new Net Zero Energy Buildings, it is difficult to analyze the buildings on just a LEED line item basis as it was just two years ago for the July 2008 ED+C article on costing for LEED, so I am asking the design teams to provide some narrative here to describe more of a “whole building design and cost analysis methodology”.  I think that the Aldo Leopold Legacy Center and the National Renewable Energy Laboratory’s (NREL) Research Support Facility buildings have changed people’s perceptions about “whole building design methodology” shifting the focus from obtaining credits to achieve a LEED rating to a more focused design methodology on achieving the new “Net Zero Energy Building” paradigm.  Each team will describe their design strategies to shift from the current costs in lighting, HVAC to energy savings concepts for walls, roofs, and renewable energy systems.

National Renewable Energy Laboratory Research Support Facility Team: Philip Macey (Haselden), Paul Torcellini (NREL), John Andary (Stantec), Dan Villeneuve (AEC), Shanti Pless (NREL)

Philip Macey (Haselden): When you consider the starting point for the RSF design, you have to recognize that the process really began with a very well crafted Request for Proposal, which DOE and NREL developed. As an owner group they had tried twice before to create a smaller version of the project, each time focusing on energy performance. For a range of reasons, most around funding they had not been able to complete the project. Ironically the second attempt was stopped when additional funding was made available and the increase was sufficient to allow a re-start of the project at a larger scale. With this change in funding level, and with a couple of incomplete attempts they reconsidered the whole project, and determined that a completely fresh approach was needed to really hit the bull’s eye. The DOE/NREL team retained the Design Build Institute and with them determined a ‘best practices’ based approach to a design competition, and settled on a best value performance based selection process. The competition was open to design build teams comprised of contractors teamed with architects, with the architects contracted under the contractor.

The requirements all focused not on prescription, which is specifying a particular type of light fixture or window glazing, but for example, instead identified the lighting level to be met under any circumstance.  Over a couple hundred pages the performance specifications laid out in detail the expectations for all the building system performance, either explicitly or by reference to a wide range of industry standards (ASHRAE, IBC, IEESNA, etc.)

There was a particular series of requirements, the Project Objective Checklist that became for the Haselden/RNL team the core of our project approach. That single page listed in ranked order the ownerships desires for a proposal. And for anyone that has participated in a competition, you can spend a great deal of time trying to understand what an owner wants, and there it was a list of exactly what they wanted. 

The list began with ‘Mission Critical’, which meant that if these items were not provided, a proposal would be deemed non-responsive and would be rejected. That first group included LEED Platinum as a contract requirement – and right away you knew this was going to be a very different project. The second group was ‘Highly desirable’ and the last group was provocatively titled ‘If Possible.’ At the top of that list was ‘zero energy design approach.’ Now we had done our home work, and knew that NREL (Paul Torcellini and others) had written a paper that outlined exactly how zero energy should be measured, meaning that as a client group they had more than just a passing interest in the idea. 

When we were putting our team together, we at RNL took the idea of zero energy as real outcome that we should try to achieve, and had scoured the nation to find an engineering partner that could bring the intellectual horsepower to the team to create that level of building design, and Stantec was clearly one of the very best in the nation, with 5 platinum projects on the board at the time and one that had the potential for zero status. We asked John Andary and his team to do something we had never asked any engineer to do, start first. We asked their team to consider the site location, the general building size, the climate, etc, and create a rough energy model to see if it was even possible to get to zero in the Colorado climate.  And they found that with some reasonable assumptions they could make it work. They brought that work to our first charrette, and just blew the room away, they had found a way to hit what we knew to be a very aggressive energy goal ( 25kBTU/SF/Yr), and do it in a way that the architecture side of the team could see would work on the site.  

John Andary (Stantec): I’ve since begun to call this “pre-concept energy consulting” and I think that in a world of zero energy buildings, firms that do what we do are going to be asked to perform these analyses as due diligence before a project can even get off the ground, in order to determine just what kind of architectural and engineering design will be required to meet the stringent energy goals of the future.   I also brought to the first charrette a rough sketch of a building section that had most of the major energy saving ideas that we ended up with on the project, such as the Lightlouver daylight bouncing device on the south wall, the slab radiant cooling and heating system, underfloor ventilation air, solar shading, thermally massive concrete sandwich panel walls, etc. This was a very crude drawing that I drew on the plane to Denver the day before our first charrette, based on the concepts we had already modeled to meet the energy goals. It is a testament to the collaborative nature of this design/build team that they let an engineer that they had never met before make such a bold proposition in the very first project design meeting.

Philip Macey (Haselden): We knew day one that if we let energy drive the architecture we could hit the energy goal, by making the building essentially a daylight and thermal energy collector. And that was a pivotal moment, making the energy of the climate the form driver. The energy model assumed two long narrow wings, oriented generally east/west, creating a building with a primary southern exposure, which allowed great daylighting, and from there practically every decision started from the perspective of linking the building to the ‘free energy’ of the climate. What that entailed was a very integrated perspective of building design, one in which building form, orientation, envelope and interiors all have an important role in dramatically lowering energy use in support of heating, cooling, lighting and ventilation. 

The overarching idea is that one of the single largest energy loads in a building is lighting energy (and when you combine that load with the cooling energy needed when the lights overheat the space you have sometimes up to 60 percent of total building energy). So we knew that if we could cost effectively integrate daylighting, without over-lighting or over-heating, we could dramatically reduce total energy. The other issue for most buildings in most climates (and definitely an issue in Golden Colorado) is that there is too much energy at the wrong time – too much heat in the day, and no way to use or capture the cool of the evening. To manage this we used an old idea, thermal mass. The building envelop is 11” thick insulated concrete panel which delays the cold transfer of winter, and heat transfer of summer. That approach is combined with water based heating and cooling, the campus central plant delivers hot or cold water through some 43 miles of radiant tubing in the floor/ceiling slabs, and it radiates down into the space below, and when combined with the wall’s thermal transfer, creates a very low energy use.  Automatic operable windows are also used to introduce cool night air to remove excess heat in the spring and fall months. Staff can also operate windows during the daytime in those same months. 

The other way the building works with the climate is to create and store energy using a thermal labyrinth.  The approach is based on the concept of remote thermal mass, and leverages the crawl space below the first floor to create a space to store thermal energy. The crawl space was required by the expansive soils found on the site.  In this building the warm air is created by a technology invented at NREL. The transpired solar collector is a thin layer of perforated dark metal that sits forward of the south wall, air is warmed by the sun on the metal, and is ducted down into the labyrinth where the energy is stored over night and used to warm the inbound air the next day.  Similarly air warmed by the buildings substantial computer center is ducted to the labyrinth and stored as well.

Other key integrated energy saving features:
  • Three part window design: vision, daylight and ventilation

  • Triple pane glazing with a carefully balanced window to wall area of 25 percent

  • Light tone finish and furniture selections that maximize daylight distribution

  • Enclosed offices primarily located on the north side, modular stations on the south

  • Modular partitions at 42 and 54,” offices at 84” with no ceilings
Of all the lessons of this project, and there are quite a few, ‘energy driving architecture’ is surely the most important.

What we found was that all design decisions are interrelated and create a multi-sided approach to problem solving. For our work we found that we needed to balance the output of five separate analyses:
  • Daylighting Model

  • Thermal Model

  • Energy Model

  • Natural Ventilation Analysis
And all of these had to balance with
  • The Cost Model
The idea is to manage the overall cost centers to transfer costs from mechanical and electrical solutions into the building architecture, and permanently lower operating costs by investing in passive strategies that leverage the free energy of the climate.

What this turned into was an approach we call Sustainable Strategies, which are a collection of 12 approaches to limiting or managing energy use (these are the choices that your design team makes with an owner to minimize building energy use), and pairing that with the way that the client team will buy or create energy, the three symbols on the left.

With all these ideas in play we found that the section was by far the most important design tool, as it allowed us to control daylight, thermal mass and natural ventilation. Better than 80% of the building follows this basic approach.

John Andary (Stantec): We like to do these “cartoon” building sections to relate how the building is intended to work and what kind of innovative strategies we are intending to implement to hit those aggressive energy goals. This is common enough in the architecture community to represent passive strategies, but the trick for us is representing the engineering systems in the same section to show the integration of architecture and engineering. The power of these diagrams shouldn’t be minimized especially when you are dealing with large, complex organizations like NREL and many diverse stakeholders want to understand what you are proposing.  

Philip Macey (Haselden): And the result of all those choices creates a very open and collaborative workplace, which is linked by great daylight and views to the climate. 

Note: See Cost / Performance Data Sheet (Download PDF at the bottom of this article)

Aldo Leopold Legacy Center Team: Tom Kubala (TKWA), Joel Krueger (TKWA), Greg Tucek (Boldt Construction), and Andy Fieber (Boldt Construction)

Tom Kubala (TKWA): I think it is important to understand the owner’s focused commitment toward achieving a carbon neutral way of operating the building. So often the true cost (to the environment) is left out of a building’s cost of construction considerations. The Aldo Leopold Foundation wished to become responsible for all the costs such a building imposes on the land. The design team’s carbon neutral marching orders shaped, more than any other factor, the approach to creating the building within real budgetary constraints. The Construction Manager participated as a full member of the design team, allowing the free flow of cost feedback as the various strategies for achieving carbon neutral operation were entertained. This approach helped to minimize the negative impact of predetermined design concepts. The overall strategy developed by the team was to have the building itself do the lion’s share of reducing it’s own heating and cooling loads, thereby minimizing our reliance of more expensive technical solutions. Dollars were then allowed to flow toward the building enclosure, the quality of it’s insulation, windows, shading performance etc.

Andy Fieber (Boldt): The whole building design approach allowed the project team (owner, architect, engineers, and builder) to make value based decisions that kept the project cost within the desired budget, i.e. costs associated with sustainable strategies are incorporated into overall budget, in lieu of becoming ‘a la carte’ items added to the overall budget.  

Note: See Cost / Performance Data Sheet (Download PDF at the bottom of this article)

Dockside Green, Victoria, British Columbia Mixed Housing / Commercial Project Team: Russ Drinker (Perkins + Will Architects) and Tavis McAuley (Busby Perkins + Will Architects), and John Andary (Stantec)

Tavis McAuley (Busby Perkins + Will Architects): Our approach to meeting environmental performance targets involves an integrated design and systems thinking approach. An integrated design process seeks to optimize the building and site’s systems (i.e., energy, water, waste, green house gas emissions, etc.) with a holistic approach where the whole of the system is greater than the sum if its parts. For example, it is of utmost importance to have the entire client and design team establish the vision and goals for the project, ensuring that there is buy-in from the outset of the project. Such a team dynamic will enable team members to understand synergies between design disciplines as they arise. More so, this approach seeks to optimize the efficiency of the systems as a whole rather than to achieve maximum efficiency of the individual parts. This integration ensures that the project achieves the client’s environmental performance targets within the economic realities implicit in every successful project.

In 2005, Perkins+Will completed the master plan for the 15-acre mixed-use Dockside Green development, which includes live/work, hotel, retail, office and light industrial uses, as well as numerous public amenities. With a LEED Platinum target for each building, it is expected to become the first LEED Platinum community in the world. In 2008 Dockside Green Residential Phase I or “Synergy” was completed and reached LEED Platinum at 63 points, making it the highest-scoring LEED Platinum Certified project in the world. Phases 2 and 3 (Balance and Inspiration) are now complete and are on target to achieving a LEED Platinum Certification as well. Dockside Green employs an integrated energy system that includes a biomass gasification plant that converts locally-sourced wood waste into a clean burning gas to produce heat and hot water. The biomass gasification system, along with selling the extra biomass heat to a neighboring hotel, has rendered the project carbon neutral on a net annual basis without the purchase of green power cer­tificates. The development’s many other sustainable features include: on-site wastewater treatment that will save more than more than 200 million liters of water annually; rooftop gardens; a car co-op with Smart Car; and, additional energy-saving features, including Energy Star appliances, heat recovery ventila­tions units, Low E double glazed windows and exterior blinds on the west and south faces of each building. A series of ponds spread throughout Dockside’s central greenway also assist in on-site storm water storage while the greenway itself provides significant public amenity space.  

Additional sustainable design measures included in the Dockside Green project includes:

Sustainable Site
  • Erosion and sedimentation control plan was developed

  • Site is on former industrial Brownfield

  • Final phase will provide a site density of over 13,500 m2/ha

  • Within easy walking distance of public transportation

  • Bicycle storage and change rooms are provided

  • Two Hybrid and alternative fuel vehicles are provided

  • Project wide reduction in parking by 29 percent from municipal by-law

  • Restoration of open space through extensive use of green roofs

  • Rainwater management visibly demonstrates rainfall capture on buildings and the flow from the buildings to the central waterway and then to the harbor

  • Rainwater harvesting is used for site irrigation

  • Approximately 90 percent of all parking will be underground

  • Combines green roofs with high albedo roofing materials for 77 percent of roof surfaces
Energy & Atmosphere
  • Uses a central renewable district energy system

  • There are no CFC-based refrigerants in the HVAC&R systems and no use of halons in the fire suppression equipment

  • Dockside includes an on-site biomass gasification system that utilizes waste wood to heat all building for space and domestic hot water heating

  • Green Power purchased for Balance

  • 71 percent energy reduction on a residential building of similar size and features
Materials & Resources
  • Incorporates easily accessible recycling.

  • Achieves a 90 percent waste diversion rate

  • Achieves an average of 16.8 percent recycled content in the building materials

  • Achieves an average of 28 percent local/regional materials

  • Incorporation of renewable materials
Water Efficiency
  • Will use no municipal potable water for irrigation, rainwater and reclaimed site black water will be used for all site irrigation

  • 100 percent of all sewage will be treated on-site at the Waste Water Treatment Facility (WWTF)

  • Water processed through WWTF will be reused for toilet flushing, green roof irrigation and to replenish the waterway and pond features

  • Project will achie a 65 percent reduction in potable water use over baseline by using dual flush toilets, low flow sinks, showers, and by providing grey water from the WWTF
Indoor Environmental Quality
  • Meets the requirements of ASHRAE 62-2001

  • Smoke free in all common areas of the building

  • Monitors Carbon Dioxide (CO2)

  • Follows a stringent construction IAQ plan and testing

  • Incorporates low VOC adhesives, paints, coatings and sealants in addition to low emitting carpet and urea-formaldehyde free composite wood products

  • Use of operable windows, combined with temperature and lighting controls

  • Meets the requirements of ASHRAE 55-2004

  • Provides daylight for 100 percent of regularly occupied spaces and views for 96 percent of spaces

  • Innovation and Design Process - Green Guidelines and product literature are handed out

  • Offers site tours and on-site signage

  • GHG neutral development 

John Andary (Stantec): Although our Vancouver office was responsible for the low energy and water conserving engineering design work on this project, I am familiar with most of the concepts employed. Of particular interest is that, unlike the others featured in this article, Dockside is a developer led project. But, similar to the other projects, the owner demanded a deep green project that made financial sense. As I have previously mentioned in this forum, real change is going to come to the building industry when owners (institutional, commercial, residential or otherwise) realize that they only need to empower design and construction professionals to create these projects and it will happen. Without such a top-down approach, I won’t say it is impossible, but the integrated process perfectly described above is likely to disintegrate, which is probably a death sentence for NZEB projects.

A fascinating aspect of all these projects, Dockside included as the only residential project, is the emphasis placed on reducing internal loads to meet the NZEB goal. I know that this was a particular focus of the Dockside team once the basic project energy pie was produced and it became obvious that a huge portion of the total annual energy consumption was from the appliances in each unit. We are getting so good at designing low energy buildings, the real future of low energy buildings is going to be focused on internal loads.

Another important aspect of the project to me is the clever method by which they achieved carbon neutrality. The biomass boiler plant creates enough energy (in the form of hot water) from a renewable source to offset the annual energy of the site, but this is more hot water than the site can use. The concept of selling the excess hot water to neighbors is the kind of triple bottom line business decision that many building/development owners can capitalize on when the site is too constrained for traditional renewables like PV.

Note: See Cost / Performance Data Sheet (Download PDF at the bottom of this article)

Marin Country Day School Team: Scott Shell (EHDD), Ken Powelson (EHDD), and John Andary (Stantec)

Ken Powelson (EHDD): The design of the Marin Country Day School was rooted in the powerful precedents of the site. The school has a strong focus on experiential learning, an integrated curriculum and a strong connection to the environment and the world around them. The campus itself had been built incrementally over many years, and had developed a language of buildings intermixed with nature and mediated by covered exterior circulation. We found that this language was remarkable adaptable in creating an energy efficient design, with narrow buildings bringing in excellent natural daylight while creating connections to nature, and covered exterior walkways providing the deep overhangs that we needed on our south and west elevations to protect our buildings from insolation. The remarkable thing was that these exterior walkways reduced the amount of conditioned space, and provided shading with no premium to the building.

The school is situated in its own watershed, with the Ring Mountain preserve to its south, west and east, and the San Francisco Bay to the north, so telling the story of water became an important part of the project. Stormwater used to run down the edge of campus in a concrete channel; we restored this to a creek, with bioengineered banks, to which our art classrooms open up.

Stormwater from the playgrounds ran directly to this stream; now they run to bioswales that reduced the amount of hardscape on campus and created new opportunities to inhabit the natural landscape. The water from our rooftops is captured in a 15,000 gallon cistern buried under the Lower School playground; it provides greywater for the toilet system, and a naturally insulated and cooled storage container for the evaporative cooling system feeding our radiant slabs. 

Our general strategy to achieve net zero energy was to drive energy usage down as low as possible, so that the remainder could be covered by photovoltaics. Originally, we assumed that the PVs would be located on the roofs of our new building, but as we investigated siting, we realized that there were sites with better sun angles located on adjacent buildings. We then turned our focus to a campus-wide study of the optimal location for PVs. It was a useful lesson that the solar component of a net zero strategy does not necessarily need to be tied to the building form, if other, more efficient and desirable locations are available. 

In the end, we found that all the design moves that we made to support a great natural daylighting scheme, great visual and experiential connections to the natural world could be justified in terms above and beyond their contributions to energy efficient and sustainable design. Great daylighting and strong connections to the outdoors creates great learning environments, places where people wanted to be, where they are energized. The Head of School put it best when she observed that the kids acted differently in the new buildings, that they were “relaxed and engaged.” There does not need to be any conflict between energy efficient or sustainable design and great design that people love to inhabit.

John Andary  (Stantec): EHDD has designed quite a number of low energy buildings. As such, the design process for MCDS was unique, given that the design team was well versed in the nature of this type of design effort. For example, EHDD knew the right questions to ask of us to get quickly to the answer of whether a design decision is appropriate to meet the energy goal. Secondly, they were willingly to accept the answers even if it resulted in a difficult design challenge for them. I mention this because I think it is indicative of how the industry is changing for Energy Consultants and MEP Engineers, like ourselves, that have not traditionally had the cache or place on a design team to promote these concepts for low energy buildings.

Note: See Cost / Performance Data Sheet (Download PDF at the bottom of this article)

LEED Cost Review of Net Zero Energy Buildings

The team discussed the entire list of LEED line items related to the Net Zero Energy Buildings.  Since most Net Zero Energy Buildings are Platinum LEED facilities, LEED is an important feature of each building.  As mentioned earlier, the focus on attaining just a LEED rating has changed in the last few years.  The focus for NZEB’s is now on integrated design concepts, decisions to save energy, and provide renewable energy systems.  The review of LEED line items will help architects and engineers prepare for NZEB by knowing what the costs are now for the new NZEB LEED buildings.

Sustainable Sites

Sustainable Sites Prerequisite 1: Construction Activity Pollution Prevention

Bruce Haxton: There is usually no additional cost related to LEED associated with this line item since the zoning and building codes define the conditions to preclude construction activity pollution.

Sustainable Sites, Credit 2: Development Density & Community Connectivity

Bruce Haxton: Dana Villeneuve, can you tell us approximately what time it takes you to develop a development density community connectivity to submit to LEED perspective?  

Dana Villeneuve (AEC): I would say that a couple of hours is reasonable.  We have these wonderful resources like Google Earth at our fingertips these days that make it very easy to map out the parks, restaurants and other community services that are located within a half mile of a project site, so it’s become a pretty quick & simple process. 

Sustainable Site, Credit 3: Brownfield Redevelopment

Bruce Haxton: The Brownfield site parameters are so site specific that this needs to be handled on a case by case basis. 

Andrew Fieber (Boldt): Abatement costs associated with brownfield sites are wide-ranging, from very small lead/asbestos abatement projects to large contaminated soil removal projects.  However, a lot of brownfield sites are located in highly sought after urban locations and Owner/Developers should use the potential site remediation costs as a negotiating tool to reduce the overall cost of the property. The abatement costs for the Aldo Leopold Legacy Center were negligible. 

Tavis McAuley (Perkins + Will): The decision to build on a Brownfield site in our experience has little to do LEED.  A developer must consider the cost of remediation within the project proforma in determining the financial viability of a given project.  Dockside Green had contamination issues which were addressed through the development, however these costs were not considered to be part of the cost of pursuing LEED.

Sustainable Site, Credit 4.1: Alternative Transportation, Public Transportation Access

Bruce Haxton: In terms of alternate transportation, I know that NREL has their campus bus system.  Were there any additional costs related to tying your new building into this campus bus system?

Philip Macey (Haselden): You know, on a number of these site points, we were fairly challenged, either by the nature of being on a campus or the location of the campus relative to the immediate neighborhood didn’t allow us to achieve the points under the terms that LEED offers.  So we didn’t particularly do anything out of the ordinary to try to get that one.  As best I understand, Dana Villeneuve, I think we got this credit?

Dana Villeneuve (AEC): SS Credit 4.1? Yes.

Philip Macey (Haselden): We achieved that because the shuttle bus ties you into RTD, right?

Dana Villeneuve (AEC): Right. Paul Torcellini or Shanti Pless may be able to speak in a little more depth about the campus shuttle system, but essentially NREL has recently expanded their campus shuttle network to make it even easier to connect NREL campus employees to the surround RTD bus stops. I cannot say how much money they’ve put into the shuttle system, or how we would factor that into a cost analysis.

Paul Torcellini (NREL): The RTD bus stop is within the quarter of a mile already.  We also provide shuttle service between our buildings.  We are on a fairly distributed campus because we lease buildings in an office park, we had the shuttle system in place.

Sustainable Site, Credit 4.2: Alternative Transportation, Bicycle Storage & Changing Rooms

Bruce Haxton: Can the teams give us some costs on what the changing room and bicycle storage facilities cost? 

Tim Babb (PTC): Yes. The biggest cost will be the additional shower. Many owners are committing to showers now days for their employees or tenants. Obviously the square foot cost is relative to the size of your building, but it’s probably a cost item that is easily met.

Tavis McAuley (Perkins + Will): For residential buildings the LEED Canada Multi Unit Residential Building Application guide requires the bicycle parking stalls to be covered and secure for building occupants. This is often consistent with local zoning bylaws of most Canadian Cities so the cost of providing these is not considered to be a LEED cost. Accommodating bicycle racks on grade is in the range of $250 - $500/stall. Change rooms in residential buildings are not a requirement of LEED. For other building types where not required by the program it is reasonable to apply the cost per square foot of the building to the area of the required change room to determine the premium cost to provide these facilities.

Bruce Haxton: Approximately what is the square foot cost for these facilities?

Tim Babb (PT&C): It would vary widely, depending on the square footage. For Aldo Leopold Center, it might be higher. For a 500,000 square for office building, it would be minimal. Bike racks are $1,000 and less. Showers will range depending on if it is just a shower, a shower and sink or a shower, sink and toilet. $25,000 – 35,000 and of course that varies widely with what finishes are selected.

Sustainable Site, Credit 4.3: Alternative Transportation, Low-Emitting & Fuel-Efficient Vehicles

Bruce Haxton: Teams please provide comments there about providing vehicle refueling? 

Tavis McAuley (Perkins + Will): We have some experience with this because the City of Vancouver recently passed a By-law that requires twenty percent of parking stalls in condominium buildings to have Electric Vehicle Charging Infrastructure. These are required to be 240V 40amp circuit and the cost to install these in a new building is estimated to be between $1000 and $1500/stall.   

Sustainable Site, Credit 4.4: Alternative Transportation, Parking Capacity

Tavis McAuley (Perkins + Will): This is one credit where there is often a financial incentive to meet the LEED requirements. The cost of underground parking is highly impacted by the cost of excavation, site dimensions and resulting efficiency of the parking structure but often exceeds $25,000 per stall. If a project can gain approvals to reduce the number of required parking stalls while still meeting the projected demands on parking for purchaser/building occupants there it is often financially attractive to provide less parking. 

To date Dockside has been granted a 29 percent reduction in the number of parking stalls required by local By-law, so you can see how that adds up very quickly. It’s hard to really argue that the savings would be $25,000 times each stall saved, but there certainly a net savings for many projects targeting this credit.

Gregg Tucek (Boldt): The Leopold Legacy Center parking lot is on grade, paved with local crushed stone as a permeable surface, and the reduction saved about $1,400 per space.

Sustainable Site, Credit 5.1: Site Development, Protect or Restore Habitat

Gregg Tucek (Boldt): Leopold was able to plant a lot of material on volunteer work days with minimal cost. 

Sustainable Site, Credit 6.1: Stormwater Design, Quantity Control

Bruce Haxton: Would the teams describe costs for storm water design for this credit?

Tim Babb (PT&C): Some of the local codes are going to begin requiring more stringent storm water requirements. I’m not sure it’s going to be a lot more money to meet the LEED requirement as local codes are updated.

Tavis McAuley (Perkins + Will): As mentioned in the project brief Dockside Green was designed around the principle of minimizing reliance on municipal potable water, and connection to sanitary and storm sewer services. This required a comprehensive site wide water management system that balances water supply (rain) with water use and water treatment.

Effectively all rainwater that falls on the site is treated as a resource to provide irrigation, water for sewage conveyance and to replenish the waterway and pond features of the site. Overall the project is modeled to achieve a 65 percent reduction in potable water use over baseline and treat 100 percent of rain water and black water on site within the Waste Water Treatment Facility. This system impacts several credits including SSc6.2 and all Water Efficiency Credits and goes well beyond the credit requirements in most cases.

Given the tailored approach to this system it is very difficult to provide a break-out cost relative to conventional municipally provided system which is effectively externalized and paid for through property taxes. The key to implementing a system of this scale and complexity is to open up a dialogue with all stakeholders, the water/sewer utility provider and potentially third  party operators and see what synergies can be achieved. In the case of Dockside green the Waste Water Treatment Facility is treating municipal sewage to supplement the sewage generated on site until full build out. This actually provides a revenue source to the project.

Sustainable Site, Credit 6.2: Stormwater Design, Quality Control

Bruce Haxton:  The storm water quality and quantity is very integrated with the last credit.  Would TKWA Architects describe the rain garden system that they had on the Aldo Leopold Center Project? The water was captured the water from the roof and it went down a designed feature into a rain garden. 

Greg Tucek (Boldt): I guess one of the cool features of the Leopold Center and how they separated the public space onsite from the “off the beaten path” area where the geo-thermal well field was located, was a feature called the aqueduct. And so half of that cost we put towards just the architectural feature. The other half ($35,000) we put in here as a cost for this credit. So it’s approximately $35,000 and that rain garden was about 4,600 square feet.

Sustainable Site, Credit 7.1: Heat Island Effect, Non-roof

Andy Fieber (Boldt): To eliminate costs associated with the heat -island effect non-roof and reduce overall project costs; the Leopold Team consciously placed the building within the existing site, in lieu of manipulating the site around the building. Therefore, the building, green space, and parking lot, blend into the natural landscape to benefit from protection of the surrounding hardwood canopy.     

Sustainable Site, Credit 7.2: Heat Island Effect, Roof

Bruce Haxton: The heat island effect on the roof; the charge on that for getting the higher quality of reflectivity on the roof is minimal I would assume?

Greg Tucek (Boldt): Yes the material selected for that was the same cost as any typical metal roof of any other color green or blue for instance that may be selected.

Andrew Fieber (Boldt): There was no additional cost associated with this credit for the Aldo Leopold Legacy Center project. The cost for a ‘cool’ roof standing seam metal material and installation is the same as it’s ‘non-cool’ roof counterpart.

Bruce Haxton: Tim Babb, I know that you‘ve been researching a vegetated roof solution under option two there. Do you have a metric for a vegetated roof?

Tim Babb (PC&T): There’s probably a fair amount of historical data out there on green roofs and these vegetated roofs. I think that the design community has gotten very efficient in being able to provide a structure and the necessary base material to provide a vegetated roof. I think in general, the cost of green roofs will be coming down as they become more prevalent.

We did some work in Washington DC and the square foot cost per the roof area itself, not the building square footage, was anywhere from $8 to $16 a square foot, depending on what you designed. 

Tavis McAuley (Perkins + Will): I just wanted to make one comment on the green roof because it’s kind of an interesting segue. One interesting aspect of the green roof on Dockside was that the developer actually sold roof garden plots to offset the additional cost of providing a green roof while providing an amenity to building occupants. I understand that these were sold very quickly in a city where gardening is taken very seriously.

So I think there are some good marketing opportunities with green roofs that maybe should be accounted for in the above capital cost analysis.

John Andary (Stantec): I generally steer clients away from green roofs in favor of photovoltaics or solar thermal panels. As much as I like green roofs for the function they provide to a project’s heat island or stormwater goals, I think that the greater problem for design professionals to solve has to do with carbon and climate change in the form of low energy and NZEB buildings. Practically speaking, this requires the incorporation of roof mounted renewables, especially considering that we want those PV panels to be providing power for a long time. As such, site mounted panels are less appropriate than building mounted panels since that site is inevitably going to have a higher future value when developed for a building. The likely result is that those site mounted PV panels will then be removed sometime in the future.

Sustainable Site, Credit 8: Light Pollution Reduction

Bruce Haxton: So what I was hearing about the light pollution topic is that the light fixtures are becoming more efficient and there is a wide selection. Manufacturers have incorporated LEED into their product design constraints and there is probably no additional cost.

Tavis McAuley (Perkins + Will): I don’t usually put a cost to this because I think it does really come down to the landscape design and the fixture selection. Usually these decisions are not made primarily for LEED, although it is one consideration on some projects. When I talk to manufacturers they have product lines that meet the requirements of the night sky at no real additional cost. They typically are on the lower end of the range because the limits outlined by the Illuminating Engineering Society of North America referenced standard.  

Water Efficiency

Water Efficiency, Prerequisite 1: Water Use Reduction, 20% Reduction

Tim Babb (PT&C): The cost will be relative to how it’s engineered to reduce the water usage. The plumbing fixtures themselves aren’t really costing a premium as most manufactures’ are producing these at competitive prices. These are becoming more common place.

Tavis McAuley (Perkins + Will): I don’t usually put a cost to this because; I think it does really come down to the landscape design and the plant selection. And usually those decisions are not made primarily for LEED, although it is one consideration. 

Water Efficiency, Credit 1.1: Water Efficient Landscaping, Reduce by 50%

Tom Kubala (TKWA): What we found is using the native plants of the area is the way to reduce water usage, and in most cases that first cost is about the same as regular landscaping materials. And maintenance costs are then significantly reduced because of a different kind of care take in those plants.  So we don’t see any uptick in costing for that – for that point.

Water Efficiency, Credit 1.2: Water Efficient Landscaping, No Potable Use or No Irrigation

Philip Macey (Haselden): In drought challenged areas deleting irrigation is not a good choice as young plants can perish without at least a couple of years of irrigation. We’ve taken the approach that this is not a wise choice in the Colorado climate do to the potential for losing recently installed landscaping.

Water Efficiency, Credit 2: Innovative Wastewater Technologies.

Greg Tucek (Boldt): The Aldo Leopold project was so innovative at the time that Kohler, a manufacturer in Wisconsin, jumped right on board and donated all the toilet fixtures for the project as a demonstration and outreach gesture.

Philip Macey (Haselden): You know on the NREL RSF project we found as was noted by one of the folks on the line that there was a relatively modest, maybe $50 per unit premium, and we saw right around that amount for the RSF. We used the Sydney Smart toilet, a dual flush toilet and as best I can tell, all the pricing for our next piece of work with NREL RSF tells us that in fact the market is pushing that $50 per unit premium downward. So I think market forces are working to take that down another step. One of the benefits to the owner is that the overall building water tap and sewer size can be dropped one full size in some larger projects, we saw that with NREL.

Tim Babb (PT&C): I concur. That’s what we’re finding. Five years ago this would have been different, but nowadays it is common place to use water saving fixtures.

Dana Villeneuve (AEC):   As Philip Macey was saying, at the NREL RSF building we used the Sydney Smart Caroma fixture, which was a floor-mounted fixture. For the next building that we’re working on at NREL, we’re actually going to try out a wall-mounted fixture that has similarly impressive water savings. 

As Philip Macey and Tim Babb were saying, prices are coming down. The marketplace is really responding and transforming, which I believe is one of the greatest impacts that LEED has had on the industry. Manufacturers are responding to the increased demand for greater efficiency, and are beginning to push the envelope more and more with their products’ designs. Achieving WE Credit 2 has been a little more of a challenge for some projects, often due to an aversion to installing waterless urinals or to taking what may be perceived as a “risk” by going a step further – composting toilets for example. 

John Andary (Stantec): The Marin Country Day School, which is a relatively small project at about 40,000 square feet, has a significant rainwater storage system utilizing a 15,000 gallon underground storage tank as previously noted. The tank is used for toilet flushing in the winter months when there is rainfall in Northern California, and then is used for cool water storage in the summer when it doesn’t rain. The cool water is produced by a cooling tower only at night (no compressors) and circulated through a radiant slab cooling system the following day. 

Tavis McAuley (Perkins + Will): This credit is related to my notes above on SSc6.1. As mentioned in the project brief Dockside Green was designed around the principle of minimizing reliance on municipal potable water, and connection to sanitary and storm sewer services. This required a comprehensive site wide water management system that balances water supply (rain) with water use and water treatment.

I would generally agree that the costs of low-flow fixtures are within base building pricing for the most part unless you get into dual-flush electronic sensors which are in the range of $150/fixture.

Energy & Atmosphere

Prerequisite 1 Fundamental Commissioning of the Building Energy Systems

Bruce Haxton: Andy Fieber could you describe the commissioning and related costs for the Aldo Leopold Center Project?

Andy Fieber (Boldt): The Aldo Leopold Legacy Center team completed the requirements for Fundamental Commissioning and Enhanced Commissioning. A project team member is capable of completing the Fundamental Commissioning requirement and Boldt incorporates these tasks into the standard project documentation procedures. There is no cost premium associated with this credit.     

However, there is an additional cost for Enhanced Commissioning and the cost varies by project type and complexity, i.e. a science lab commissioning fee is more likely higher than a library commissioning fee.  Based on experience, Boldt estimates third party commissioning fees at 1/10 of a percent to 1 percent of construction costs.

Tavis McAuley (Perkins + Will): That really depends on the building. I think your notes from the previous discussion on laboratories were pretty accurate which noted fundamental commissioning seems to be part of the process in owner occupied buildings. But when we look at condominium buildings, there’s no commissioning effectively that’s being done on these buildings so it can be a $20,000 to $30,000 + cost depending on the size and complexity of mechanical systems. Related to this the cost of EAc3 Enhanced commissioning which requires 3rd party review during design and construction which can add another 20% to the cost of achieving EAp1.

Prerequisite 2 Minimum Energy Performance: 10% New Buildings or 5% Existing Building Renovations.

Prerequisite 3 Fundamental Refrigerant Management:

Bruce Haxton: Tim Babb, do you have any input on that?

Tim Babb (PT&C): No, Bruce. I think you’re required to do this in most areas so there is no additional cost.

Credit 1: Optimize Energy Performance 

Bruce Haxton: It is very difficult to define the costs under this credit since in an integrated design approach spreads the costs and savings under many different components. There’s a premium cost for a high mass structural to dampen temperature, extra building skin (due to added floor to floor height) to achieve daylighting, roof slope for collector angle and daylighting, under building labyrinth for air temperature control, night-time ventilation to cool the building, under floor HVAC distribution in the building, evaporative cooling systems, high efficiency T 8 direct and indirect pendant fixtures, and LED task lighting. The true test is to try to add up the additional costs and savings, then compare. Another test is to compare the building performance metrics, operating metrics, and the building costs.  

Philip Macey (Haselden): When we were getting ready for this call, the thing that we struggled with a bit was the concept of extracting a premium, in the sense that everything in the form of the building was driven from a first position about energy as a form driver, as a form maker.

So what Paul Torcellini, Shanti Pless, and I had the opportunity for conversation just earlier this morning, and what we wanted to share at this point in the discussion was that “incrementalism” is possible in the LEED format.  It kind of invites you to enter the discussion from any point. You know, you can create a LEED opportunity for your project, maybe very much around the use of the site because there’s some particular advantage there. And so you can take a sort of an incremental approach. 

We came to our project from a fundamentally different starting point. The NREL RSF is a paradigm shift.  The project illustrates that if you enter the LEED discussion from the position of lowest overall energy consumption, it will drive a number of your choices and they don’t necessarily create premiums. What you do is create a lot of cost and value tradeoffs. 

The skin is our largest cost center in the project and that’s no surprise. We have almost twice as much skin on that building as you would in conventional, simple five story box. If you do the math on the NREL RSF building a typical architecture for the 220,000 square feet would have been a reasonable five story building, and be a big office park kind of a building. And I don’t want that to in any way sound like a critique or pejorative. That’s just the nature of the building that you’d typically get. 

Having said that, that’s exactly the kind of building that I think practically everyone on this call doesn’t want to make anymore. The owner set an aggressive energy goal—this set the form of the envelope and the rest of the systems cascaded into place. Many of the LEED points then just happened. I think primarily what we would like to share with the readership is that what we’ve learned is that the shift to get beyond Platinum is a fundamental change in the paradigm. If you start from energy, you end up with a different outpoint. 

The skin does several things. It does keep the weather out, it also helps heat the building and cool the building. And the backside of the panel is actually finished to a degree that it actually is the interior finish of the building, and there is no interior drywall. The widows are sized for daylighting and views which substantially reduces the lighting (and related cooling) loads.

So although we paid what one might consider a premium for the skin, by making that element of the building do other jobs of the building, we’ve essentially invested in other decisions that now cost you zero. As far as we are concerned, the way we spent money on the envelope resulted in no additional building costs. 

Bruce Haxton: I’m glad you said it the way that you said it because I couldn’t have said it any better than you.  

John Andary (Stantec): There was a lot of that “cost transfer” concept going on as we made critical choices on how to spend money to balance cost and energy models. For instance, as you have already heard, the window-to-wall ratio is around  25 percent, which you would not normally see on a contemporary office building. The majority of the cost of a wall assembly is in the glazing and, because we only have enough glazing to provide appropriate daylighting, natural ventilation and views, the cost per square foot of skin is much less. This falls into the minus cost category along with, for example, no acoustic ceiling due to the radiant slabs, no drywall on the interior of the building, etc. Examples of items in the plus cost category are the extra square footage of the sandwich panel exterior walls, the radiant piping in the slabs and the lightlouver daylight bouncing product. In a project that adopts a good integrated design process these kinds of “cost transfer” activities can occur and the result is a high performance building for the cost of a traditional building. 

Tim Babb (PT&C): You and I have talked about this synergy, so I think this gets important. You may spend X amount of money on a credit but it may get you other credits along with other functionality. It’s very hard to put a number on this but I agree with Philip Macey. There’s a synergy here and it looks like Perkins + Wills is aware of it. It’s hard to isolate all of these costs.

Bruce Haxton: I think you’re actually correct because, you know, on the Leopold Center, the way that the light was brought into the building, it’s a little higher than normal probably. You pay a little premium there but you gain some things. So I agree with you totally.

Paul Torcellini (NREL): The other thing that we gained on the 60 foot cross section was we have no columns interior to the space, so that gave us a lot more flexibility--that has value back to space efficiency, which means we can build a smaller building and put more people into it. In addition, everyone has access views because of the narrow cross-sections. These two items have value to the building as well as providing a mechanism for energy savings.  All these pieces are important. 

Philip Macey alluded to it, we (the owner) established the energy goal upfront. It was a fixed cost. And then we hired the design build contractor to meet our goals, and energy was one of them, within that fixed price.  And we selected that contractor based on their ability to get there.

Paul Torcellini (NREL): There was no extra money. Philip Macey’s comment about neutral cost is true for this project. We did not have extra money to build this super energy efficient building. We had very typical building budget for federally procured project.

Bruce Haxton: NREL has described it in the way that it needed to be described, and I see Tom Kubala here nodding, that’s exactly correct from his perspective too. 

Tavis McAuley (Perkins + Will): One of the challenges that I think, that a condominium building has relative to a lot of owner occupied or government-funded projects is that the developer isn’t holding onto the building.  So any potential savings in energy consumption can’t really be transferred to his pocket over the lifetime of the building or even over a several year span. 

That being said, I just want to point out some fundamental things. I have gone through about 16 of our LEED Certified/targeted projects and found that points associated with EAc1 typically represents about fifty percent of the total LEED incremental costs of the project. So this where we focus a lot of efforts on optimizing building design to minimize operating costs.

We look at energy conservation measures in a pyramid. At the bottom of the pyramid is the low hanging fruit with minimal capital cost impact. Things like building shape, orientation, and engaging building operators and occupants to conserve energy. This is followed by passive strategies such as increased thermal performance of the building envelope and building design that maximizes natural ventilation and passive solar heating. The most costly means of achieving energy efficiency is through applying active systems such as higher efficiency mechanical equipment and on-site renewable energy systems.  Decisions about what approach to use on a given project are typically made by the design team in accordance with the client’s operational savings objectives, environmental impact expectations and construction budget. However depending on the building type and owner/developer flexibility, the ability to incorporate the most economical measures can be limited. This is especially true in the case of condominium buildings, where there are very specific program expectations and there is little opportunity for alternative floor plan layouts that could optimize energy efficiency. Floor plate design is predicated on optimizing the salable-area-to building-area ratio, and unit layouts are restricted by small unit sized and marketplace trends. Furthermore condominium purchasers are attracted to energy intensive designs such as floor-to-ceiling, wall to wall glazing, pushing exterior glazing ratios to 85 percent of total exterior wall area in typical condominium buildings.  Although this approach to designing the building envelope may be cost-effective initially, glazing areas exceeding 40 percent make it progressively more difficult to achieve energy efficiency in an economical way. 

In Dockside, I think we were able to balance passive strategies with active strategies to achieve an 85 percent reduction in energy relative to the reference building. I would agree with the notes by others above in that the costs related to EAc1 need to be considered in a comprehensive way as there are synergies to each system considered. During the design process we work closely with energy modeling to balance the life cycle cost of energy conservation measures to optimize the building over a specified period of time. 

For example at Dockside we worked with passive strategies that address thermal comfort and Indoor Air Quality which are typically concerns in these types of buildings. We incorporated solar shading devices that eliminate the need for cooling effectively. This had huge cost savings advantages over conventional buildings. Centralizing the domestic hot water was both more efficient and eliminated the additional area associated with providing this equipment in each suite.

Similar to the Waste Water Treatment Facility described above Dockside Green employs an integrated energy system that includes a biomass gasification plant that converts locally-sourced wood waste into a clean burning gas to produce heat and hot water. The biomass gasification system, along with selling the extra biomass heat to a neighboring hotel, has rendered the project carbon neutral on a net annual basis without the purchase of green power certificates This again is owned and operated by a 3rd party which reduces the capital cost of installing the associated plant equipment in each building, and ongoing liability to the strata corporation. On project of this scale we are seeing this increasingly as utilities can provide long-term secure investment vehicles for operators and can significantly reduce.

Credit 2: On-Site Renewable Energy

Bruce Haxton: Would each team member describe their experience with there project’s renewable energy systems?

Paul Torcellini (NREL): The PV was the one element that was not part of the building budget.  We designed the building to be “PV-ready.”  We did not have the luxury of adding additional elements to the building because of the fixed-price cost. The PV was funded by a third party that we purchase the energy from. They have a longer time investment horizon and were willing to make the investment.

Credit 3: Enhanced Commissioning 

This section was discussed under the commissioning section.

Credit 4: Enhanced Refrigerant Management

John Andary (Stantec): There isn’t really a cost for this anymore if the design engineer that is familiar with the current refrigerant options on the market. What I find really significant about that comment is that it hasn’t been that long since the issue of ozone depletion became well known, which pushed this topic to prominence by the general public. Since then the air conditioning industry has stepped up and developed cost competitive alternative solutions. This on a small scale is what we hope to achieve on the much larger and complex scale of carbon footprint reduction. Industry will indeed react to the public’s demands.

Credit 5: Measurement and Verification

Tavis McAuley (Perkin + Will): For condominium buildings there’s not a significant premium. The CaGBC published the Multi-Unit Residential Application guide which addresses unique characteristics of this building type. It is standard that every unit has separate billing for electricity. In Dockside they also have the capacity to measure water and thermal energy consumption for space heating and domestic hot water. These meters average $1000 - $1500/inch diameter however are not a requirement of EAc5 for condominium buildings. Overall the LEED premium we identified was around $10,000.

For the retail and office building components of the project we have a similar level of metering however here we identified it as a LEED cost totaling around $45,000 or $2.5/sf. This included lighting system control at $850 each, motor loads at $1500, air distribution static pressure at $6000, boiler efficiency/thermal loads at $3500, building related process energy at $3-5/amp, and water meters at $1000 - $1500/inch diameter. We also include a cost of around $2000 for a consultant to prepare the M&V Plan.

Credit 6: Green Power

Bruce Haxton: This credit is so site and building specific, we will just state that this needs to be studied on a project by project basis.

Materials & Resources

Prerequisite 1: Storage & Collection of Recyclables

Bruce Haxton: What I’m looking for here is the amount of area that the teams have allocated to storage and collection of recyclables a metric as to what that costs. 

Philip Macey (Haselden): We generally see that you need a three compartment recycling space or room (glass, paper, plastic) for every 100 people. Depending on the city or jurisdiction it could be a single multiple waste stream container. At NREL we carried a room per floor at 60 SF.

Credit 1.1: Building Reuse, Maintain 75% of the Existing Walls, Floors, and Roof

Bruce Haxton: This credit is so site and building specific, we will just state that this needs to be studied on a project by project basis.

Credit 1.2: Building Reuse, Maintain 95% of the Existing Walls, Floors, and Roof

Bruce Haxton: This credit is so site and building specific, we will just state that this needs to be studied on a project by project basis.

Credit 1.3: Building Reuse, Maintain 50% of the Interior Non- Structural Elements

Bruce Haxton: This credit is so site and building specific, we will just state that this needs to be studied on a project by project basis.

Credit 2.1: Construction Waste Management, Divert 50% from Disposal

Greg Tucek (Boldt): The Legacy Center simply set up the appropriate recycling program to obtain this goal – I think most contractors are finding there is actually a cost savings associated with even modest recycling programs.

Credit 2.2: Construction Waste Management, Divert 75% from Disposal

Tim Babb (PTC): On the waste issue going from 50-75 percent in many cases is just physically impossible and does not come down to cost.  It just can’t be done for most projects.  So there is no known metric, it would have to be looked at on the case-by-case basis.

Dana Villeneuve (AEC): Yes, it can be very difficult to achieve the 75 percent threshold in certain areas of the country which do not have as many facilities & processes in place for material recycling. Oftentimes this obstacle can be overcome by performing additional due diligence early on in design and pre-construction to find the right waste streams for your recyclable materials. 

Credit 3.1: Material Reuse

Dana Villeneuve (AEC): In my experience, I don’t perceive a significant premium associated with Regional Materials Credits 3, 4 and 5, (reused, recycled and regional materials). Rather, it’s a matter of ensuring that your project team intends to make these strides with their material selections from day one. So long as you are thinking about how to best source your materials from early on in the design, and are willing to do the legwork to find those reused or recycled alternatives, you can succeed without experiencing many cost impacts. It’s about doing your homework, with environmental impact in mind, well before specifying your materials.

Philip Macey: (Haselden): There are other ways to look at this credit beyond achieving the credit, the concept itself is important. The RSF project used only reclaimed steel pipe for all of our structural steel (reclaimed natural gas pipe) and did not encounter a premium for the material. We did a lot of homework to have the materials tested and field checked, all in all we saw just shy of a 2 percent premium on the materials. But under the standards for this credit we didn’t meet the cost threshold to get the credit, and for us it was still important to the sustainable position of the project.

Credit 4: Recycled Content, 10%, (Post –consumer + ½ Preconsumer)

 Refer to narrative above Credit 3

Credit 5: Regional Materials, 10%, Extracted, Processed & Manufactured Regionally

Bruce Haxton: The Leopold Center did not really have a premium on the regional materials just because of the way it was designed, but I think in most cases it’s dependent on where the building is; whether it’s out in a relatively unpopulated area where there’s not much manufacturing around it or whether it’s in a place where product manufacturers’ are all around and you’ve got access to many materials.

Gregg Tucek: Buddy Huffaker, the Ex. Dir. of the Leopold Foundation, made a great analogy to his young son – who builds with what is available – legos and Lincoln logs, he doesn’t search out exotic materials.  The Center was designed and built with the same thought – what is available and how can it best be utilized in and with the building.

Credit 5.1: Regional Materials, 10%, Extracted, Processed & Manufactured Regionally

Dana Villeneuve (AEC): I just wanted to say in my experience including NREL project, I don’t think there is a premium cost that you could associate with Regional Materials Credits 3, 4 and 5, the reuse, recycled and regional. It’s largely just as it is with all LEED credits, it’s a lot less expensive to do these things so long as it’s your intention from day one and so long as you’re really thinking about them from day one, then it’s pretty easy to find the right products to specify that are high in recycled content or that do come from within 500 miles of your project. 

It’s very often not any more expensive to source the right product. It’s just a matter of taking the time upfront to do the homework and figure out what those products are. 

Credit 6.0: Rapidly Renewable Materials

Dana Villeneuve (AEC): For Material & Resources Credits 6 & 7 (rapidly renewable and certified wood), the cost premium is more of a reality. Rapidly renewable building & finish materials tend to be more expensive than their conventional counterparts in many cases. However, I think the case could be made that in several instances the rapidly renewable product is of much higher quality and/or durability, lending to a reasonable life-cycle costing argument for selecting rapidly renewable products. 

Credit 7.0: Certified Wood

Dana Villeneuve (AEC): Likewise, for Credit 7, the cost premium exists. Many of the projects which I have worked on have achieved this credit due to the fact that they had only a small amount of wood on the project, making it relatively easy to get to the 50 percent threshold associated with the credit, if not using 100 percent FSC-certified wood. 

Tim Babb (PTC): The certified wood is a problem because there is not as much of it and that does create a premium. Obviously it comes down to what species of wood you are looking at. I guess one could say it could be a premium of 25-50 percent more depending on quantity, type i.e. millwork, furniture, panels, trim etc. I think Dana Villeneuve’s comment that if you have a small amount of wood on your project it becomes more feasible. If you have a lot it may become cost prohibitive.

Indoor Environmental Quality

Prerequisite 1: Minimum IAQ Performance

Prerequisite 2: Environmental Tobacco Smoke (ETS) Control

Tavis McAuley (Perkins + Will): For condominium projects where there is a mix of smoking and non smoking units there is a cost to controlling smoke transfer between each residential unit. We have found that this is a fundamental change in the way that the sorts of construction details in partition walls are done typically. We typically carry an additional $500/unit to allow for sealing at the floor/ceiling/wall intersections and sealing any outlets located on demising walls. We also carry $1500/ blower door test to demonstrate compliance. The credit also requires you to weather strip the entry door which is often designed to leak in conventional condominium mechanical designs. So this changes the means by which fresh air can be supplied to the unit. Typically we see these issues are being addressed as part of the larger energy consumption strategies.

Credit 1.0: Outdoor Air Delivery Monitoring

Bruce Haxton: Tavis McAuley, was the metric from your project – $500 a point for monitoring outdoor air delivery?

Tavis McAuley (Perkins + Will): That is typically what we carry for each required sensor. This is not a particularly expensive credit to target for condominium buildings.

Credit 2.0: Increased Ventilation

Philip Macey (Haselden): We saw no cost for that. Largely because we have a building that doesn’t heat using air, and so being thirty percent over what they required was no problem.

John Andary (Stantec): The cost was there but somewhat hidden on the NREL building since this design item was always intended to be part of the project. Like the NREL building, the industry is moving toward decoupling ventilation systems from heating and cooling systems. Clearly, when you increase that ventilation system by thirty percent to meet this LEED point, then you’re definitely going to have an increased cost of air handling equipment and ductwork.

Philip Macey (Haselden): I don’t think there is anyway you can get away from that increase in energy use in an air based system. It’s a very obvious increase, for all air systems particularly, but with water based heating system, then you’re not going to see as much of an increase. There’s going to be a small energy hit because you’ll have to cool or heat that additional fresh air. But I’d say that that decoupling air supply from tempering, that’s happening as a state of the art level of HVAC design, but given the increasing costs for energy it seems it won’t take long for that to become standard practice.

Tom Kubala (TKWA): In central Wisconsin, where winter outdoor air temperatures can easily reach minus 20 degrees F., the decision to provide 100 percent of ventilation demand with fresh air required that we look at a low cost (first cost and operating cost) strategy for tempering incoming fresh air. Energy modeling revealed that a passive earth tube array would be much more effective than an Energy Recovery Ventilator (ERV) and offer a significantly smaller carbon footprint into the future.

Tavis McAuley (Perkins + Will): For condominium projects where ducted ventilation in the suites is rare this can be an expensive point to target or not feasible depending on the buildings mechanical system. I would carry an additional $500 - $1000/suite to bulkhead and duct to each living space assuming you have ducted ventilation to each suite.

Credit 3.1: Construction IAQ Management Plan, During Construction

Greg Tucek (Boldt): Yes. We have a lot of experience in health care projects, so we understand the importance of maintaining cleanliness during construction – you cover up open duct work and filter the air.

Philip Macey (Haselden): We used to see something in the range of .10 - .25 / SF, but in the last 2-3 years that seems to have left the market, provided you make it a requirement for all bidders from the start.

Credit 3.2: Construction IAQ Management Plan, Before Occupancy

Philip Macey (Haselden): Same comments as above.

Credit 4.1: Low-Emitting Materials, Adhesives & Sealants

Dana Villeneuve (AEC): I would say that I’ve seen no cost premium for low-VOC adhesives or sealants.  Very often a low-VOC version of a product will be right on the shelf next to the high-VOC version, with little or no cost difference between the two. 

Credit 4.2: Low-Emitting Materials, Paints & Coatings

Dana Villeneuve (AEC): I have experienced little to no cost premium for paints & coatings, and as with all EQ Credit 4 products, a small premium is certainly worth the health of your installers and occupants. 

Credit 4.3: Low-Emitting Materials, Flooring Systems

Dana Villeneuve (AEC): In working with the interior designer on the RSF project, Wendy Weiskopf, I’ve learned that there is no cost premium associated with CRI Green Label Plus carpet products. Likewise, I would say that most compliant hardsurface flooring products can be obtained with little or no cost premium. Regulated products run the gamut – vinyl, rubber, hardwood, ceramic, etc – and the cost associated with product selection is based upon material selection and design preferences, rather than LEED requirements.

Credit 4.4: Low-Emitting Materials, Composite Wood & Agrifiber Products

Dana Villeneuve (AEC): There is definitely a cost premium associated with purchasing composite wood products that are free of urea-formaldehyde. Essentially, you’re talking about purchasing exterior-grade product for all interior applications. In my experience, this credit is pursued more often than not. Perhaps the concept of healthy indoor air quality is tangible and immediate enough to sway the majority of owners and project teams to dedicate a little bit of additional money to compliant products.

Credit 5: Indoor Chemical & Pollutant Source Control

Dana Villeneuve (AEC): For the most part, the items addressed by this credit are simply good design practices, which a project would incorporate into their design regardless of LEED. However, the requirement for all outside and return/recirculated air to be filtered with MERV 13 media can be a costing and design challenge for some projects, depending upon their selected mechanical systems.

Greg Tucek (Boldt): The Leopold Center built a floor mat system out of on-site materal at a lower cost than a purchased one

Credit 6.1: Controllability of Systems, Lighting

Philip Macey (Haselden): Relative to controls, actually the opposite is true, NREL wanted a very simple system, having seen many owners struggle with complex systems that users can’t operate. We have a quality system, used to its best, but made a lot of choices to keep lighting controls simple.

Paul Torcellini (NREL): We do have a lighting control system in the building. I would not characterize it as unusual. We do have vacancy sensors so that people have to manually turn the lights on manually turn them off. If occupants forget to turn them off, the lights are swept off at the end of the day. We also have dimming controls on the light fixtures to respond to the daylighting. 

Credit 6.2 Controllability of Systems, Thermal Comfort

Greg Tucek (Boldt): The Leopold Center was very hands on so that you turn a knob at your desk to let more air in or not. 

Philip Macey (Haselden): Controllability for occupants comes from two simple approaches, vents in the floor, and operable windows. The scroll vents are a standard part of under floor air systems. Operable windows are a part of the building skin doing the cooling so we don’t see that a premium.

Dana Villeneuve (AEC): We have a very smart building management system at the NREL RSF, which alerts occupants as to when it is ideal to open & close a window. However, we’re actually not achieving EQ Credit 6.2 on the project, as we have a ratio of workers in open office areas to operable windows in the area that is above 2:1. Our under-floor air distribution system provides ventilation, but not heating and cooling, so it therefore does not provide enough thermal control to space occupants to meet the credit’s requirements. 

Paul Torcellini (NREL): The occupants can adjust their airflow. Then there’s a manual diffuser that they can open and close.  The office zones do have an adjustable thermostat. 

Credit 7.1 Thermal Comfort, Design

Dana Villeneuve (AEC): I see no cost premium associated with designing to meet ASHRAE Standard 55.

John Andary (Stantec): Understanding the nature of the relationship between thermal comfort, architecture, interior design and cooling/heating systems is crucial to designing low energy or NZEB buildings on a budget. This is not well understood in the design community and far too complex a topic to delve into in this forum. However, my recommendation to design teams is to budget time and resources for thermal comfort simulation work on your low energy project. There is potential for substantial payback in energy savings and HVAC system cost reduction.

Credit 7.2 Thermal Comfort, Verification

Dana Villeneuve (AEC): Developing a thermal comfort survey which meets the requirements of LEED is a pretty quick process, which typically only takes a couple of hours. Using an online tool such as the Center for the Built Environment’s survey, which is available for purchase on their website, can be a great way to go for a project team that does not have previous experience developing and administering the survey. 

Greg Tucek (Boldt): The Legacy Center installed a permanent temperature and humidity monitoring system that would be similar to any other commercial building project, so with minimal, if any, premium cost. As part of the commissioning process, the system is tested to ensure it works as intended, confirming that the small investment will pay dividends for years to come. 

Credit 8.1 Daylight & Views, Daylight 75% of Spaces

Tom Kubala (TKWA): That has all to do with the building shape. What we did was maximize our perimeter in order to increase the amount of wall to admit daylight to each individual in the building, so how you put a metric to that; I really don’t know but that was the intent anyway?

John Andary (Stantec): On the NREL RSF we have the Lightlouver devices that bounce light over 30 feet into the building from the south face. This was needed to have 100 percent workspace daylighting in a 60 foot building cross section. In addition, everyone has a view out a window - but that view glass is separate from the glazing for the daylighting. 

Bruce Haxton: That’s good that you mentioned that.  On one of my buildings I designed, the width was 45 or 50 feet to get that daylight. 

Credit 8.2 Daylight & Views, Views for 90% of Spaces

Dana Villeneuve (AEC): Achievement of this credit does not have a premium associated with it, but rather is dependent upon building programming & interior partition design. Keeping as many occupied building spaces along the perimeter, and utilizing low or transparent partitions for those occupied spaces within the interior, are the real necessities.  

Innovation & Design Process

Credit: Innovation in Design: Green Cleaning

Dana Villeneuve (AEC): Green cleaning was not one of the strategies used on the Research Support Facility project but I have been a part of several other projects which have elected to use green cleaning products. Taking the time to develop a Green Cleaning Program for your facility may be a small cost, but the premium on purchasing green cleaning products rather than conventional, toxic products is minimal or non-existent. 

Credit: Innovation in Design: Educational Outreach / Buildings That Teach 

Dana Villeneuve (AEC): One of the Innovation in Design points which we did pursue at the Research Support Facility was Educational Outreach/Buildings That Teach. This is a simple credit which many projects pursue. We designed educational signage which is installed throughout the building, highlighting some of the project’s green features. We also have a kiosk in the lobby that provides real-time data to occupants about the operations and energy usage of the building. Phil Macey could probably provide some information regarding the costs associated with our display screens. 

Philip Macey (Haselden): We budgeted $20,000-25,000 for two displays and all the software and programming to drive the information to the screens.

Credit: Innovation in Design: Sustainable Teaching Aids

Tom Kubala (TKWA): Well with certain projects we’ll put a brochure together, you know, that is an educational process for people visiting or touring the building, and that can range all over the board from a simple brochure for $5,000 to video introductory programs and more advanced booklets and brochures, you know up to $50,000.

Bruce Haxton: One of the things that I’ve used in the past proposed projects was a model of the building itself in a metal casting way so that a blind person who’s experiencing the building can actually have a sense of what the building is. You can also go into, a motion actived audio description of the facilities and the description of sustainable parameters of the project. 

Comments by Software Manufactures about Net Zero Energy Buildings

Dimitri Contoyannis (IESVE): There have been several common themes brought up during today’s discussion. It boils down to the fact that there is a strong synergy between many of the LEED credits. Our software platform is designed to model a building’s energy performance building while accounting for these inter-relationships.  

In a typical LEED project, there are a number of credits that you’re likely to pursue that will have an influence on the energy performance. Let’s look at some of the issues discussed here as an example.  The light pollution reduction credit can be achieved by reducing the amount of installed exterior lighting – fewer fixtures means less electricity, so that will have a benefit on your energy performance. To achieve the water use reduction credits, you could use low flow fixtures – that will lead to less domestic hot water consumption and therefore less natural gas energy consumption by the water heater. Good daylighting with a light dimming system can lead to electricity savings from the lighting systems and potentially the cooling systems.

One of the attendees noted that they considered upgrades to the building envelope as an investment which would pay dividends in terms of energy savings. I’d also like to point out that increasing the envelope’s performance can lead to smaller building loads and therefore smaller HVAC equipment. This is a first cost savings opportunity that needs to figure into the economic analysis. 

The key take away is that there are a number of different strategies that can lead to a building’s energy savings and if you look at the building holistically, you have the opportunity to realize the most benefit. You can find that, things that are as simple as just the building’s form can have a profound impact on energy savings. That’s something that effectively requires no additional investment but is just a smart design decision. 

We really encourage people to get involved in the energy modeling of a building from day one. Even if you have a few design sketches up on the board, start to analyze them and determine which building form is the best inherently. Then, as the design progresses, add more details and continue to assess which design options lead to the greatest savings. 

Jason Pratt (Autodesk): I would definitely echo all of that. Our mission at Autodesk is to provide the industry with, the technology to help augment and enhance design and construction of buildings, primarily through better analysis and simulation. One of those areas is BIM-enabled takeoff, which is you know, fast growing and a pretty exciting concept. 

BIM-enabled takeoff gives project teams the ability to see, the cost and quantity impact of various changes to the baseline design or proposed design, like changes in the form, changes in the width, changes to the exterior envelope and so forth. We think the quicker that you can get those results generated and feedback into the design and into the cost process, ultimately the better performance, better sustainability and lifecycle cost the buildings will have. 

So it’s all about lowering the feedback loop between making a design change or proposing a design change and finding out what’s the cost in quantity and performance impact of that change. We want to shrink that loop to the minimum.

So with tools like Revit and Autodesk Quantity Takeoff, we’re already seeing teams getting eighty to ninety percent reductions in the time that it takes to generate takeoff quantities versus the traditional process, which gives you more time to focus on, all the interactions, (environmental) and material and performance variables that you have on the project and less time tracing drawings with highlighters and measuring and using calculators to try and understand what these costs are.

So we’re just thrilled to be able to participate in helping designers, supporting them in their efforts to create, a better built environment for us all. We know that LEED and sustainable design and building performance analysis have a really bright future, and we’re proud to play our part.

Andy Smith (Bentley Software): Designing for net zero energy performance requires a process that supports multidisciplinary design optimization allowing designers to take advantage of the interactions between disciplines and the sharing of complex engineering data. For example, the evaluation of design alternatives for building massing and footprint to optimize energy performance requires a review of the site impacts for civil grading, the influence of on-site renewable energy and storm water management. An efficient iterative design process will allow each discipline to evaluate its specific impact on the energy savings, sustainability and construction costs and contribute to the project at large. Our AEC design software (e.g. Bentley Architecture, Bentley Structural Modeler, GEOPAK Civil Engineering Suite, and Bentley Map) provides a collaboration platform for multidisciplinary design optimization. 

At the core of collaboration is interoperability allowing project participants to share data but yet use different applications. Interoperability allows for BIM data to be used for multiple purposes, cost estimating and annual energy simulation (e.g. Bentley Building Mechanical Systems, Bentley Hevacomp, and Bentley TAS Simulator). Our support of industry standards (e.g. gbXML - Green Building XML and IFC - Industry Foundation Classes) allows for the sharing of data with other applications and the flexibility to use the analysis tool of choice. Although, there are some cases when direct interoperability provides benefits. For example, an electrical designer using our BIM application (e.g. Bentley Building Electrical Systems) can improve the energy performance of a design by quickly evaluating the quality of lighting against the watts per square foot using an analysis tool such as Acuity Brands Visual Pro.

The contribution that software providers can make to delivering net zero energy buildings is to provide design and simulation tools to the design and construction community that makes efficient multidisciplinary design optimization. The broad sharing of design information and exploitation of interactions between disciplines will improve the process for evaluating performance versus costs resulting in better designs and higher performance buildings.

Michael Bendewald Rocky Mountain Institute (RMI) about Life Cycle Cost Analysis (LCCA)

I would just make one comment before getting to the topic of lifecycle cost analysis, really to build off the whole systems design conversation that has been happening. I think this project to get a better handle on some of the line-item costs of LEED credits is extremely valuable. But for some credits, especially the ones having to do with energy, it is clear that this information can be misleading.

The designers at this roundtable have rightly pointed out that building design is most effective when decisions are made to provide multiple benefits from single expenditures. For example, a decision to paint the walls a lighter color and use indirect lighting can achieve aesthetic objectives as well as make a room seem brighter despite less lumens. A need for fewer lumens can result in fewer luminares (saving capital cost) and reduced heat gain (saving cooling cost). In some cases, the cooling load can be reduced so much as to downsize the HVAC equipment, saving even more capital cost. Making decisions that provide three or more benefits will allow you to achieve more LEED credits and get closer to net zero energy for little or no added cost. As Paul Torcellini mentioned, there really was no added cost for the new net-zero NREL facility.

So, switching to lifecycle cost analysis, I was asked about how peak oil might influence the financial evaluation of a more energy efficient building design. Peak oil is the theory that oil will eventually reach its maximum production capacity, before entering a slide to zero. Based on the economic laws of supply and demand, as oil production decreases, the price of oil will rise, reflecting the scarcity of the commodity.

Oil is directly used in some buildings for boilers and to the extent that its close cousin natural gas is used— which is basically just a very small carbon string instead of a very long one. They are used primarily for heating buildings, or cooking food. To the extent that the building energy efficiency measures will lessen the need for natural gas or oil for heating, peak oil would make the case for implementing such measures even more financially attractive. Additionally, since the prices of oil and natural gas are loosely correlated, it's also possible that peak oil will put upward pressure on the price of electricity since natural gas can make up a substantial percentage of the fuel that powers the electricity system where the building is located.

No one really knows what energy prices will do. The US Energy Information Administration projects electricity cost escalation at about 2.5 percent each year. The EIA also captures natural gas costs. In addition, the market indicates the price of natural gas through the sales of futures, but these only extend 5 years out. If you think we have already hit peak oil, which some have claimed, and oil prices will, say, double from $80 to $160 in 10 years, then you could double the price of natural gas in your financial model over that same time period. The price of electricity is less straightforward, but you could make the increase proportional to percent of natural gas in the power supply.

But before you do any extensive analysis into energy cost projections, it important to just get an understanding of what energy costs would have to reach in order to change your investment decision. After you have a better understanding of what that “tipping point” is, you can then look backward and forward at the cost of electricity and natural gas. Does your “tipping point” fall into the range of where costs have been? How close does it come to future projections? Is it too close for comfort?

I will add one final comment on the cost of carbon, which is an increasingly important parameter to include in financial evaluations. If United States (US) policy were to shift closer to that of the European Union (EU), the cost of emitting carbon dioxide, assuming our current mix of fuels for power generation, would equate to roughly a 10 percent increase in whole-building energy cost.

Bruce Haxton: The price of oil right now I think is, about $78 – $80 a barrel, and right now if you look at the production curve of oil, we’re really at the peak between 2007 and 2012, somewhere after the peak the production will be going down.

Michael Bendewald, from Rocky Mountain Institute, I would like to see what happens to the cost information with Life Cycle Cost Analysis when the price of oil goes from the current value of about $80 per barrel to $100, $120, $140, and $160 a barrel oil?

The oil costs are may be going to go up soon. What kind of an impact will the future cost of oil have on the NZEB decision-making for buildings in the future? I think that that’s a very important topic. Could you try to obtain information about the impact of oil price increases. There is important information in the book “Plan B 3.0” authored by Lester Brown.

I know that when we talk with Rick Cantwell who’s on the teleconference call, we looked at some projects; the same is true for water, only it’s tough to put a price on it. But right now water is going to be in short supply, if not already there in China, India and some of the other Asian countries, and in the Southwestern United States. So we have some water resource problems that will continue into the future. 

Philip Macy (Haselden): It appears to us as we looked at the NREL Research Support Facility project, stepping back from it as the folks who had a chance to design and construct it, we began to consider the idea that we’re looking at a new class of real estate. That in fact the inflection point that we’re at seems to be leading us to a condition where the rising cost for energy combined with the rising performance of PV and geothermal systems, combined with much more precise energy modeling might be bringing us to an inflection point.

Quite possibly projects that are zero energy and zero water seem to our experience to be marking a starting point. As was offered earlier in the conversation that the Dockside Project is pursuing zero water, and the NREL project is on track for net zero energy, it seems to us that in fact that is the answer, that buildings and development that actually retain or create the utility investment, be it water or power, or in some way have a benefit towards the treatment of the effluent that leaves the building, are in fact the kind of buildings that we want to create. They’re net contribution is much more beneficial to things in general, and in the case of creating energy are net cash positive.

Tavis McAuley (Perkins + Will): Vancouver and the province of British Columbia are very much involved with some progressive policies both at a municipal and provincial level to raise the bar on the minimum thresholds and provide incentives to go beyond minimum code compliance.  

We are also seeing in Vancouver there is a lot of leadership from the private sector as well just in terms of going out there and being adventurous about investing in sustainability. I think it does come down to a fundamental understanding that, the public is interested sustainability and willing to pay a premium for it. So I hope through meetings such as this we bring some awareness to how we quantify the costs of green buildings and also sell the advantages to the tenants, occupants and owners who will ultimately live and work in these buildings.

Bruce Haxton:  I just want to say that I’ve appreciated the effort that everyone has taken to make this NZEB: Cost Analysis and Cost Modeling Teleconference happen.

We are all trying to provide the tools so that architects can plan for the buildings because, as a professional architect, we’re responsible for achieving people’s expectations and delivering projects within actual budgets and on time. That’s a pretty difficult task at times, especially when we’re trying to do innovative things like NZEB’s.

Key Summary and Closing Points

National Renewable Energy Laboratory, Research Support Facility (Philip Macey, Haselden): What we’ve seen is that if you start with an end in mind, start with an energy goal, which for a Colorado office building is about 25 kBTU/SF/Yr, you can get to a very low energy use at competitive costs. It is possible today to get to 50 percent below ASHRAE 90.1. It does require thinking with a fresh perspective on all the old standards, and that means reconsidering the workplace from the modular and office sizes all the way to the materials of the skin. High performance buildings have some important differences in how they are approached:
  • Much more front loaded approach to design so that the whole team is engaged early to make integrated decisions.

  • Start daylight and energy modeling at the concept phase, and allow both to drive architecture

  • Make interior design an active part of the energy solution (office sizes, panel heights, finish colors)

  • ·Pair collaboration and energy reduction to create a new and invigorating workplace, make all appliances Energy Star or better

  • Use Hydronic heating and cooling whenever possible, use natural ventilation for night cooling whenever possible.

  • High performance requires innovation and is best delivered in a design build model, using performance specifications, with merit awards for innovation.
John Andary (Stantec): A very important aspect of this, as seen in the NREL building, is not just design team integration (integrated design process). What is desired is the true integration of architecture and engineering design. On the RSF building, if any one component of the major architectural features is eliminated, there is a significant effect on the engineering systems, which results in greater energy use or a complete redesign. A perfect example is the integration of the glazing system and the radiant cooling/heating system. The chilled slab system has a limited cooling capacity by its very nature. That system can only function properly if the heat gain from the building envelope is minimized, especially solar heat gain. Therefore, the solar shading system, glazing units and the daylight bouncing system must all be fine tuned to work effectively with the radiant system. This is a great example of architectural/engineering integration.

The Kubala Washatko Architects NZEB Summary (Tom Kubala): ‘To build on a piece of land without spoiling it.’ When Aldo Leopold’s dictum is taken seriously, it requires the builder to look closely at what is necessary to create a building with a carbon footprint well within one’s own budget. Cost effectiveness has a whole new meaning when seen from the perspective where a building is a continuous, living part of a cultural/natural.

Perkins and Will Architects NZEB Summary (Russ Drinker, Tavis McAuley, and Zaki Mallasi): The terminology specific to climate change is just starting to be understood by the North American public. However, realistic strategies to help the public effect measurable change need to be offered to stem off disillusionment and disengagement with the rhetoric of environmental awareness. Keeping track of progress will allow people and businesses to be more accountable for their impact on the environment, and will allow organizations who make progress to be recognized for their accomplishments.  Government legislation can also encourage the development of business responses to environmental concerns. Financial tools such as the carbon management standard proposed as part of the Kyoto Protocol, or a form of carbon tax can provide the necessary incentives for the production of creative market-driven solutions. By pricing GHG-intensive activities and products to reflect their full costs consumers will naturally move away from discretionary GHG intensive activities.

The construction industry and associated regulatory policy makers hold responsibility for a significant portion of national GHG emissions. If nations such as Canada and the United States are committed to reducing GHG emissions, buildings constructed today need to work in service of that goal. New constructions, which will be in operation for the next century, will have a significant impact on the ability of future generations to continue to build a more sustainable society.  It is in everyone’s best interest to begin building that society today.

EHDD Architects NZEB Summary: We have long practiced integrated design, where the client’s needs and desires and the building’s modeled energy performance together driving building form. And yet we are realizing that it is not enough to expect building performance to solve our energy problems; we need to work with our clients to broaden the potential for reducing our energy footprint in the way that we live in our buildings. We have been able to do this by helping the client understand the impact of reducing plug loads in increasing energy efficiency and reducing the building’s capital cooling cost, by working with user groups to understand how building operation can affect energy performance, and to extend reduce our transportation footprint though the extended use of carpooling. We all need to be working together in an integrated fashion to find new ways of living that work in concert with technology to reduce energy consumption and to put us on a more sustainable path of living.

Bruce Haxton: Once again I just want to thank everyone. You’re providing a tremendous service to the profession. I think your efforts are making great strides in helping the existing professionals and professionals-in-training to understand the new Net Zero Energy Building design paradigm.

Summary/Lessons Learned/Tips

·         Dana Villeneuve (AEC): By making energy performance a top priority and using a holistic approach to their designs – from passive strategies to the integration of complex energy systems – the projects included in this article clearly portray the value of a strong team and an effective, whole building design approach.  I think that it is noteworthy that in many of these projects, the engineers are driving the design more than the architects. These projects are shining examples of effective integrated design.

·         Philip Macey (Haselden): The key contribution of LEED has been the creation of both the measures for sustainable design and construction and most importantly the establishment of sustainability as a market force, it has changed what clients expect, and what they are willing to buy in their buildings.

  ·         John Andary (Stantec): When discussing the cost of green buildings, I think it has to be mentioned that there are additional soft costs that come along with these super high performance buildings. We are kidding ourselves if we think that the average building owner or developer is going to spend upwards of $200K, like we did on the RSF, for energy modeling and simulation work on their building unless they see the direct monetary benefit. The monetary benefit is actually there, but a more in depth analysis is necessary to prove the value proposition. In other words, it’s another cost transfer opportunity. The energy consulting work actually saves both first and long term costs, and that should be a consideration so that every design team has the tools available to create these kinds of high performance buildings.

Along the same lines, the fees for design professionals are inevitably going to be larger as we are faced with developing more and more innovative solutions that haven’t been designed and implemented before. The architecture / engineering industry is incredibly competitive. When innovation is compromised by financial performance, most firms will not   I think the industry needs a mid-course correction on professional fees. This will go a long way toward the mass roll-out of high performance buildings.

  ·         In the past few years the LEED Rating System has been very “transformative” in terms of sustainable product design, whole building design methodology, energy analysis and now Net Zero Energy Buildings and Carbon Neutral Buildings.  

 ·         The LEED line items and related cost are becoming more “totally integrated” into a new design, energy, performance and cost paradigm. Building and product costs that just a few years ago were considered additional cost items over and above the normal building costs are now “standard.” The “standard of practice” is having the “bar raised.”

 ·         Design teams are selected to solve specific building designs. While the architect still typically serves in the role of team leader and coordinator, they do not always drive the design as they did in the past. They share the “driving” role with many of the other team members, whose input is critical in solving facets of a sustainable building’s design. Energy modelers are providing critical information on the manner in which different systems & materials perform, sustainability consultants solve complex design issues surrounding everything from daylighting performance to LEED documentation, engineers are introducing and promoting innovative design concepts and design-build contractors are working to help teams hit economic and environmental performance goals on time and on budget. 

  ·         Net Zero Energy design shift in costs in mechanical systems, lighting systems, and cooling systems;  to create energy conservation strategy solutions in higher performing walls, glazing systems, passive air heating / cooling approaches, and renewable energy systems.

  ·         Focus on reducing the energy requirements for the building, then identify renewable resources that can be used to satisfy the remaining energy needs.

  ·         In cold climate and hot climates underground HVAC systems my reduce energy costs by either heating or cooling the incoming air by with coordination of ground source heat pumps.

  ·         Glazing type, placement and size can be modeled to maximize natural daylight while managing solar heat gain.

  ·         Interior light shelves & devices can be utilized to direct light further into the floor space while exterior architectural features (louvers, fins & screens) and landscaping can be utilized to manage excessive solar heat gain & glare issues during hot summer months. 

  ·         Narrow floor plates and increased floor-to-floor heights are optimal building form selections for the maximization of daylight distribution.  Floor plates from 45 to 60 feet are used in a few NZEB to optimize natural daylighting.

  ·         The roof structure can be sloped to accommodate solar electric and hot water solar collectors. 

  ·         Heating degree days, cooling degree days, solar clear days, proximity to hydro generation facilities, proximity to geothermal renewable resources, proximity to ocean/river/lake cooling, wind speed / duration, strong hail storms (detrimental to solar devices), and extremely high winds are all site parameters that can be used as site determinants for site selection to take advantage of renewable energy resources.

  ·         Exterior solar screens, deciduous trees, solar light shelves and solar exterior louvers that direct light to the interior of the building at the appropriate time of year may be part of a whole building design strategy to reduce energy requirements and improve daylighting opportunities.

  ·         Light colors on interior design elements tend to reduce lighting energy needs since the elements reflect light.

  ·         Dense exterior walls with high insulation values will help the building performance, thermally.

  ·         Labyrinth and HVAC ground tubes used for preconditioning outside air along with heat pumps and ultraviolet bacteria control can be part of a way to passively reduce temperature differential for outside air coming into the building.

 ·         Simplified and user controlled building systems may save additional energy and promote user control over their environment and also be beneficial in time of energy outages. In other words let the building shell accomplish as much of the energy work as possible, passively, requiring the occupants to be mindful of the environmental conditions in which they are immersed. Make the means by which the passive shell is controlled straightforward, intuitive and non-engineering based. This approach will possibly eliminate or at least greatly reduce the need for mechanical systems in the first place along with their associated highly sophisticated control systems. This may or may not save money in the construction budget, but it does allow the design team to shift dollars from mechanical systems to the building shell.

  ·         Make a concerted effort to reduce plug loads, thereby reducing energy needs and costs. Main drivers of plug loads include large CRT monitors, older desktop computers, individual printers at workstations, personal space heaters, and small refrigerators at workstations. A small refrigerator can use as much energy as a standard residential unit.

  ·         Well-facilitated design charrettes and other interactive team decision-making sessions are critical to the successful promotion of whole building design strategies, integrated design solutions, and reduced energy and building costs.

  ·         Energy budget contingency planning helps to reduce construction costs and meet energy budgets with low cost solutions.

  ·         Cost control includes contingency cost planning related to design contingencies, bid contingencies (if the project is a design/bid/build project), and construction contingencies.

  ·         Investigate federal, state, and local grant opportunities related to energy conservation.

  ·         Minimization of on-site parking through public transit and carpool incentivizing can reap significant savings, as appropriate for your project. On-grade parking spaces can average $1,000 - $1,500 each, while structured parking can reach as high as $35,000 per space. 

  ·         Reduce site hardscaping to the extent possible to lower paving costs.

  ·         Reduce site footprint can save significant landscape and hardscape design costs.

  ·         Carefully assess existing landscaping during design to incorporate building and parking placement into existing tree configuration, reducing landscaping costs and capitalizing on shading potential. 

  ·         Weigh first cost, life-cycle costs, and maintenance costs with overall environmental performance for each building element in order to arrive at appropriate design solutions. 

  ·         Build a quick ‘black box’ generic geometry model of the building in a simple software program (such as Google SketchUp) at the beginning stages of conceptual design, and use industry tools to investigate appropriate building forms and orientations for the site. Develop an energy model of the building in schematic design and design development to provide comparative information about the performance of different building systems.

  ·         The owner needs to set energy goals, not change them, and hold the design-build team responsible for meeting them.

Additional Resources

Note: Websites noted below are noted here to help people and professionals find information. The validity of that information is the responsibility of each person or professional to verify.

Energy Efficiency &Renewable Energy, AUGUST 2010, 2009 Renewable Energy Data Book

Renewable Cost Related Information

California data base that may be helpful calculate renewable power.  

Website that may be helpful for electrical generation payback

Website related to Geothermal Information 

Website related to Wind Energy information

Website related to Ocean Cooling Information

Solar Information Websites:NOTE: The discussion of the NZEB roundtable on cost analysis and cost modeling is meant to be a starting point for a greater dialogue and investigation about sustainable and NZEB costs. The information in this discussion is for a special building on a special site with idealized square footage. It is meant for discussion purposes and is not meant to promote one system over another; the information should not be taken and applied to another buildings or sites. Each site is very special and the analysis and costs and solutions are specific to that particular site. When dealing with sustainable and Net Zero Energy Buildings and campuses seek professionals with experience in each and every aspect of the building you are working with. Regarding cost analysis information for architecture, seek professional cost consultant expertise to design facilities.

© Copyrighted September 2010 Bruce Haxton. This work may not be reproduced in whole or in part without written permission of Bruce Haxton. All rights reserved. 


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