October heralds the Green Building Challenge ’98 — the international conference that will bring together teams from around the world to develop a comprehensive framework within which to determine what constitutes the quintessential green building. The conference “is an opportunity to learn about building performance assessments and to see examples of ‘best practice’ green buildings from around the world,” according to the main sponsor of the conference, the CANMET Energy Technology Center of Natural Resources Canada. After two years of research and analysis by the sponsors and numerous international teams, organizers hope to help create a framework to assess in detail the energy and environmental characteristics of buildings worldwide. Each participating country has formed it’s own team, with the U.S. contingent led by the American Institute of Architects’ Committee on the Environment (COTE) and the U.S. Department of Energy. What follows is a brief description of each of the projects the U.S. team is presenting:

The EPA Campus at Research Triangle Park

Architect: Hellmuth, Obata and Kassabaum (HOK) Inc.

Owner: U.S. Environmental

Protection Agency Internet: www.epa.gov/rtp/new-bldg

When the design for the new EPA research facility in Research Triangle Park, NC, began in 1992, the government had only just begun to start its push for more environmentally sensitive buildings. Even so, the architecture firm of Hellmuth, Obata, and Kassabaum (HOK) still managed to incorporate an extensive array of green design into what will become, upon its completion in 2001, an embodiment of the EPA mission and an example for new construction projects around the country.

The 1.2 million-square-foot, eight-building campus includes 635,000 square feet of office space, as well as laboratory space for 2,200 employees. Four key “green” issues were addressed during the construction of the headquarters: ecosystem protection to preserve natural plant and animal life and air and water quality; energy and water conservation, which involved high-efficiency electrical, mechanical, and architectural features; pollution prevention, both during the construction phase and on through the life of the building; and indoor environmental quality, with the goal of a safe and comfortable work space, full of daylight and insulated from high levels of noise. According to Sandra Ford Mendler, AIA, architect and senior designer with HOK and a member of the project’s design team, “we were very comprehensive on this project and took every opportunity to think about environmental impacts of every building system.”

The extent to which the project meets the environmental criteria is commendable. Ecosystem protection, for example, has involved measures such as the minimal disturbance to the site’s natural ecosystem, strict forest protection, and stringent protection of nearby lake and streams (including lake testing to ensure water quality). Landscaping will be ultra-low maintenance (reducing fertilizer, water, and fossil fuel use) and will be derived from native species, while stormwater run-off is channeled to the lake, but not before being filtered through strategically placed filtering vegetation. A volunteer “plant-rescue” was even conducted before construction began to preserve the “inherent and intangible value” of the native flora.

Energy use at the facility will be reduced through energy-efficient lamps and ballasts that are set up for daylight harvesting, which together with occupancy sensors and task lighting will reduce electricity use by 70%. A high-efficiency HVAC system, controlled by an off-the-shelf Building Automation System (BAS), will help cut energy consumption even further, for a total reduction of 40% over a comparable government facility.

Three, 30-foot-wide atria are distinctive features of the project, not only because of the natural daylight infiltration or attractive areas for circulation and informal meetings but also because a specific combination of energy-efficient glass and translucent material was chosen after modeling of the atria on simulation software. That modeling process helped reduce operational costs by 66% over those associated with an all high-performance glass atrium.

The interior of the building is full of environmentally sensitive features and design often seen only piecemeal in other projects. Low-VOC paints, sealants, adhesives, and other materials keep indoor air quality high, as does a strict control on formaldehyde and other contaminants in construction materials. Finish material application will be phased to avoid the adsorption of contaminates by things like carpeting or ceiling tile. Wood products were purchased from “well-managed” certified forests.

For proper indoor air quality, ASHRAE-55-1992 and ASHRAE 62-1989 have been adopted, and ventilation rates are set at 100% for laboratories and 20 cfm per person in the office areas. Extensive modeling helped locate the air intake and exhausts. Meanwhile, all specified materials were screened for their affect on indoor air quality. An A/E firm was also hired by the EPA to develop a 150-page Indoor Air Quality Facilities Operation Manual that documents the necessary IAQ procedures during building construction and maintenance.

The Thoreau Center for Sustainability

Architect: Marsha Maytum Tanner Leddy Maytum Stacy Architects

Owner: Robert Wallace/Tom Sargent National Park Service/Thoreau Center Partners

Mechanical Engineer: Flack & Kurtz Engineers

Electrical Engineer: Flack & Kurtz Engineers

Consultants: Architectural Lighting Design The Office of Cheryl Barton (Landscape Architect) Tipping & Associates (Structural Engineers) Simon & Associates (Environmental Materials Consultant)

One of two renovation projects picked by the Green Building Challenge team, the $4.1 million Thoreau Center for Sustainability provides an ideal case study for the integration of historic rehabilitation and environmentally sensitive development.

Under the direction of architect Marcia Maytum of Tanner Leddy Maytum Stacy Architects, the historic wards of a former military hospital in the Presidio National Park near San Francisco were transformed into a 75,000-square-foot complex that contains office space for 20 nonprofit organizations. The project, named after Henry David Thoreau, is part of a larger public/private effort to renovate the former U.S. army base near the Golden Gate bridge into what is now known as the Presidio National Park.

At $55 per square foot, the Thoreau Center’s budget was anything but extravagant. That didn’t stop the design team from incorporating a host of environmentally sensitive features, such as natural ventilation, environmentally sensitive materials, superior indoor air quality, low-maintenance landscaping and reduced paving, and, most importantly, the recycling and transformation of historic buildings into productive facilities.

By working with the developer, tenants, the National Park Service, the Federal Energy Management Program (FEMP), the Lawrence Berkeley National Laboratories and the National Renewable Energy Laboratory (NREL), the design team was able to formulate a low-energy use strategy that included energy-efficient mechanical, electrical, and lighting systems. Low-energy lighting, for example, was achieved through T8 lamps and electronic ballasts, as well as through the use of occupancy sensors in strategic areas, giving a range of 15 to 45 foot-candles for office areas and a power density of 1.06 watts per square foot.

Shallow floor plates and a benign climate allowed the use of operable windows and natural ventilation in lieu of mechanical cooling, while high-efficiency boilers and motors, simple and effective controls, and variable speed pumps kept energy use to a minimum. According to Maytum, although the Center does not “set records” for low energy use, it does show that a historic renovation limited by a low-budget can still greatly conserve energy usage.

Environmentally sensitive materials included acoustical ceiling tiles from Armstrong World Industries, medium density fiberboard (MDF) from Medite, panels made of wood from sustainably harvested forests from Architectural Forest Enterprises, wall panels from Homasote, cellulose insulation from GreenStone Industries, low-VOC carpeting from Collins & Aikman, linoleum (a product derived from natural materials) from DLW Linoleum, ceramic tile from Terra Green, and low-VOC paint from American Formulating and Manufacturing (AFM).

Through a separation and recycling program operated at the construction site during the project, 73% of all debris was recycled, including 19.2 tons of scrap metal, 380 tons of inert fill, and 137 tons of wood. All tenants utilize local and central collection spaces for ongoing recycling.

Other small but important touches included bike storage, locker rooms, and showers for bicyclists, and electric car parking and recharging facilities.

Durant Middle School

Architect: Gary Bailey, AIA, Innovative Design

Owner: Wake County School System

Mechanical Engineer: The Wooten Co.

Electrical Engineer: The Wooten Co.

Students at the Durant Middle School are no different than those at any other school in the Wake County Public School System. But chances are they will attend school more frequently, do better on tests, and even grow taller and have healthier teeth. Why? Because their school admits ample quantities of natural light into every classroom.

Designed by the architecture firm of Innovative Design in Raleigh, NC, the Durant Middle School is one of a handful of schools in North Carolina designed to incorporate daylight into every classroom. Rooftop monitors aligned on an east-west axis bring daylight down through mitigating baffles and into classrooms. Sensors adjust artificial lighting to compensate for cloudy days. The designs were informed by DOE-2 simulations and vindicated by the results of the firm’s own studies and similar ones by the Alberta Department of Education that demonstrated the benefits of daylight in classrooms:

Schoolchildren in schools with full-spectrum lighting had greater attendance records and better performance, and, in the case of the Alberta study, had better dental records and even grew more.

Notably, the architects have managed to incorporate daylighting into the schools at only a fraction above typical first cost and in the long run have actually saved the Wake County School System money via lower energy bills. The $12.3 million Durant school was outfitted with monitors and high-tech lighting design for only $230,000, a cost reduced by half due to downsized chillers. This, plus the displaced electrical demand, allows the school to save over $120,000 in energy costs per year over a non-daylit school in the same area. The facility averages $0.70 total energy cost per square foot. Through daylighting and other energy-conserving features, the school achieves a 60% reduction in total energy load.

Cambridge Cohousing

Architect: Bruce M. Hampton, AIA, The Green Village Co.

Owner: Cambridge CoHousing

Mechanical Engineer: Paul F. Padua Associates

Electrical Engineer: JLB Engineering

General Contractor: CB Construction

Modular Construction: Epoch Corp.

Consultants: Oaktree Design Building Science Engineering

An environmentally planned neighborhood nearing completion in Cambridge, MA, is the only residential project on the U.S. GBC ’98 team. Initiated by Oaktree Development, the Cambridge Cohousing project represents an innovative and promising model of collaboration for community residents and green-thinking professionals. Oaktree, based in Cambridge, is a founding member of the GreenVillage Co., a consortium of housing professionals working with the U.S. Department of Energy’s Building America Program to mainstream energy-efficient, environmentally responsive homes.

“One of the challenges for residential construction is being able to take long-term costs and environmental impacts into account,” says GreenVillage spokesperson Stella Tarnay. “The cohousing development model, which involves extensive resident participation and long-term community investment, works very well with these kinds of environmental goals.” Because Cambridge Cohousing residents wanted a community that would be healthy and resource-efficient for many years to come, said Tarnay, this created many opportunities for environmental innovation.

You don’t need a car to get to Cambridge Cohousing, just take a short walk from the Porter Square transit station. Proximity to mass transit was an early planning goal of residents, and part of GreenVillage’s overall strategy to reduce energy use. The project not only utilized neglected urban space – thereby reducing automobile traffic, increasing urban vitality, and even providing more green space by moving parking spaces to an underground, naturally ventilated garage – but also incorporated increased efficiency and quality into units themselves. “We had a commitment to a systems approach to building,” said Tarnay. “And that meant not only working within an existing urban context but also designing for the best solar and site orientation and building efficient, healthy homes.”

Situated on a 1.4-acre former industrial site, the $9.6 million, 63,000-square-foot project includes 41 living units and extensive community facilities. Although it has many amenities, the cost of the project is just below average for housing in the area. A large common house offers informal meeting space, a kitchen and dining area, children’s play space, guest rooms, offices, a library and exercise room. The first group of residents is already shaping a community garden on one of the site’s open areas. Because parking is placed underground, the site has 20,000 square feet of open green space. Tarnay credits the reasonable costs of the project to GreenVillage’s systematized approach to building and modular construction by Epoch Corporation, also a member of the consortium.

The prototype EcoDynamic homes for Cambridge Cohousing were designed in collaboration with the U.S. Department of Energy, which provided important R&D funding for developing a system-wide approach to green building. “It is really a series of innovations that make the housing at Cambridge Cohousing work from an environmental point of view, rather than a particular technology,” says Mark Kelley of Building Science Engineering, a GreenVillage Co. member.

Those system-wide innovations include passive solar orientation, tight modular construction, well-insulated building envelope and adjoining walls, and centralized heating and ventilation that integrates ground source heat pumps. (A $10,000 grant from Commonwealth Electric supported development of the geothermal heating system.) The units themselves are made from durable, low-impact and recycled materials wherever possible. They include resource-efficient floor trusses made of 2x3 members, Hardiplank fiber-cement siding, high-efficiency Pella windows, IAQ-beneficial hardwood floors, energy-efficient appliances, cellulose insulation, and recycled glass tiles. “And the modular building process is resource efficient to, as well-managed production can produce 30% less waste than stick construction,” said Tarnay. All units undergo blower-door tests before occupancy.

The overall environmental achievements at Cambridge Cohousing are a good precedent for multi-family housing. Kelley estimates that the project will use 60% less energy and produce 40% fewer air pollutants during its lifetime, while residents look forward to saving about 50% on their energy bills. A side benefit of the ground source heat pump system is that it does not exhaust into the neighborhood or require noisy compressors. There are air quality benefits as well: a high-efficiency, balanced mechanical ventilation system ensures a continuing supply of fresh air, and all residential units have zoned temperature controls. Low-VOC carpets are installed where hardwood floors are not possible. The Harvard School of Public Health is collaborating with GreenVillage and residents to monitor indoor air. The National Renewable Energy Laboratory is providing energy performance testing.

Ridgehaven Green Demonstration Building

Architect: Alison M. Whitelaw/Jackie Lu Platt/Whitelaw Architects Inc.

Owner: Environmental Services Department, City of San Diego

Mechanical Engineer: McParlane & Associates Inc. Electrical Engineer: Turpin & Rattan Engineering Inc.

Consultants: Lynn Froeschle Architect (Environmental Consulting Architect) Gottfried Technology Inc.

The Ridgehaven Green Demonstration building in San Diego, CA, is proof that even low-first-cost buildings can be renovated and reused as a healthy workplace with outstanding energy-efficiency. (see “Renovating Ridgehaven into a Successful Green Office Building January/February 1998 Environmental Design & Construction)

After purchasing the 73,000-square-foot building in 1994, the City of San Diego’s Environmental Services Department (ESD) decided to not only renovate the building for its own use but also to utilize green building materials and design during the process. By recording the details of the project and the performance of the finished product, the ESD hoped to demonstrate just how much a conventional building can be improved. All this, despite a restricted budget and the tight scheduling typical of a municipal project.

To achieve the goal of energy use of 9.0 kiloWatt hours per square foot per year, new mechanical and electrical systems were designed carefully. Mechanical equipment, which included high-efficiency water-source heat pumps (EER 14.9), condenser water isolation valves, variable air volume handling boxes, direct digital controls, and a floating loop controller, was subjected to an extensive commissioning process to ensure optimum performance.

Other efficiency measures included T8 lamps supplemented with task lighting, daylight harvesting and occupancy sensors, solar control window film, and shorter systems furniture partitions to maximize daylight penetration. After the remodeling, energy usage dropped from 20.5 kWh/sf-y to a commendable 8.7 kWh/sf-y, saving the city $76,000 per year and making the building one of the most efficient in San Diego. The building uses 62% less energy than a nearly identical office building nearby that has not undergone energy-efficiency upgrades.

To insure indoor air quality, a primary concern for the ESD, construction material product data, samples, and safety data sheets were researched and analyzed for minimal chemical emissions, toxins and carcinogens, and VOC’s. Material selection included low-VOC paints, sealers and stains, perlite ceiling tiles, and low-VOC carpets, wallboard and countertops.

Materials were also analyzed for their environmental sensitivity, prompting the selection of such products as ceramic tile, linoleum flooring, and recycled toilet partitions. To help the team select the appropriate materials, a matrix of environmental criteria was developed and points assigned to relevant characteristics.

Resource consumption was addressed not only through material selection but also through reuse of existing materials such as ceiling panels and salvaged light fixtures, recycling of construction debris (over 40 tons diverted from landfills), and even promotion of resource conservation through colorful kiosks that inform visitors of the project’s environmental features.

According to the design team, the end result of the project was exactly as planned: “tangible results are seen in employee health, morale, and productivity as well as extensive financial savings due to reduced energy consumption.”