NREL Science & Technology Facility, a LEED Platinum lab. Copyright, Bill Timmerman.

Spearheaded by MHTN Architects, ED+C magazine participated in an original roundtable event on of the real costs of LEED certification for labs (of varying size and scope). In this unique, in-depth on-the-record discussion, industry experts explored and analyzed some of the big issues and often overlooked or understated details. The team also discussed the National Renewable Energy Laboratory (NREL) Research Facility in Golden, Colo. The NREL actual costs were compared to the EarlyEco computer run using the NREL parameters.

Roundtable Overview

The purpose of the LEED Laboratory Roundtable was to discuss sustainable solutions for research laboratories and to identify the potential costs and savings for those sustainable solutions. Mortensen Construction has just competed the NREL Research Facility in Golden, Colo., which was approximately an $18,800,000 facility with 72,200 gross square feet. MHTN Architects Inc. has developed the E$pec and EarlyEco software programs to anticipate and forecast potential LEED costs. Both Mortensen Construction and MHTN Architects, Inc. have agreed to share their sustainable cost estimating knowledge with the readership. LEED for Laboratories has not yet been issued by the USGBC. The Cost Roundtable is anticipating that the LEED for Laboratory requirements will soon be issued by the USGBC. Note that not all credits were investigated and discussed.

The roundtable included moderators Bruce Haxton and Michelle Hucal, and participants Dan Amon, Janet Baum, Glen Beckstead, Cara Carmichael, Gabriela Klieman, Paul Mathew, Geoff McMahon and Sean Wennerstrom. Full biographies on the experts can be found below. Here is a significant selection from the two-day event’s transcript.

LEED Laboratory Cost Analysis Overview

Haxton - Mortenson Construction has just completed the National Renewable Energy Laboratory (NREL), in Golden, Colorado. They supplied the team with input forms for EarlyEco that consists of 40 items. The EarlyEco works by itself or works in tandem with the E$pec estimating system and anticipates what the LEED costs and savings on a credit-by-credit basis. The EarlyEco program output identifies LEED credits, cost per square feet, relative first cost, annual savings, simple payback in years, LEED-related professional design fees, and total approximate cost. The last two column lines permit the owner to identify what they feel is most sustainable for them. By dividing the total approximate cost by the sustainable index you obtain the cost per sustainable unit. This cost per sustainable unit permits the sustainable professional to identify the most cost effective credits with the highest sustainability for the site and client.

At the beginning of design, MHTN presents the full list of sustainable opportunities for a project, showing the wide range of potential options. The client can then describe their vision of the project and what their specific sustainable goals and budgetary parameters are. Once their goals and budget are defined, the design team can focus on how to accomplish those goals within the client’s budget. When both E$pec and EarlyEco are used together, they can anticipate both the traditional construction cost and the LEED credit costs. The EarlyEco system also has the design synergies built into the computer program formulas within the program. However since the software system is not automatic it still requires experienced sustainable team members like Glen Beckstead, Bruce Haxton, or Cara Carmichael and other very experienced sustainable consultants and estimators to use the software in an intelligent fashion to include potential synergies among sustainable design solutions.

MHTN has been asked numerous times if the EaryEco and E$pec software are for sale. The computer systems need the experience of the MHTN staff to fully utilize their capabilities; therefore the systems are not for sale. However MHTN is sharing its knowledge with the readership in hope of furthering cost effective sustainable designs.

LEED Laboratory Programming Phase

Baum – In the early part of the design process, we start with programming, and when we are doing a project that we know will be LEED Certified or even just complying with LEED guidelines, we look at the exhaust devices that might be required in the laboratory and understand the operating or performance characteristics of the ventilation system. For cost control, we start in programming to model construction costs. Because the cost is intimately connected with the square footage, we track any changes in the square footage.

Entire Building Systems Design Approach

Carmichael – It seems like each credit has very individualized cost implications when really, buildings should be thought of as many systems working together. If we consider the idea of tunneling through the cost barrier where there are capital cost additions as well as cost subtractions. I wonder if we could create an alternate reference list on what other factors might weigh into this. For instance, on a site where a green roof were incorporated which reduced overall stormwater runoff and resulted in smaller drainage systems, perhaps the calculator could indicate the synergies between strategies?

LEED Laboratory Mechanical Systems

McMahon – I want to go back to something that Cara Carmichael said in the last section relating to whole building solutions. That is the key to cost control. Having cost estimating capability coupled with energy cost impact analysis — plus additional first cost analysis — is critical to the process. By doing that, you can enhance the team’s ability to make good decisions about which measures to incorporate into the design process.

LEED Laboratory Credit Cost Discussion

Haxton – The cost analysis team discussion consisted of four hours of discussion regarding sustainable laboratory designs, costs, savings and LEED credits. The narrative was significantly reduced into an article to describe to the readership the impact of costs on each LEED credit. The LEED credit cost discussion is listed below by LEED section, credit, and prerequisite.

SUSTAINABLE SITES

SS Prerequisite 1: Construction Activity Pollution Prevention

Beckstead – Many jurisdictions are making this a code requirement. Do not consider it a cost for LEED if it is a code requirement. It is difficult to price in a particular building without understanding where the facility is at, and knowing the various conditions such as slope, but a good average is about $.07 per square foot of site.

SS Credit 2: Development Density & Community Connectivity

Beckstead – Development Density is a matter of doing the calculation and determining if you meet the credit. This task may range from about $2000 to $5000.

Credit SS 4.2 Alternative Transportation: Bicycle Storage & Changing Rooms

Beckstead – For Credit SS 4.2 most people think if they put in a bicycle rack they will get a point and it will be very inexpensive. The showers and changing rooms can be expensive. If you’re already building them, you can take advantage of them very inexpensively. What I do is provide bike racks for 5 percent of the occupancy of the building.

Credit SS 4.3 Alternative Transportation: Low Emitting & Fuel Efficient Vehicles

Beckstead – For Option #1, provide vehicles for 3 percent of the building population. Rather than buying them, I rented them. I could get a price that was reasonable so I rented the vehicles. Option #2: Provide preferred parking for low-emitting and high-mileage vehicles. I have a $150 sign up for 5 percent of the total people to cover the preferred parking requirement.

Credit SS 4.4 Alternative Transportation: Parking Capacity

Beckstead – For preferred parking capacity, the size of the parking is not to exceed the zoning requirement. In this particular case, I am showing a $72,000 savings on your laboratory building because there is less parking. There is a savings in putting in less asphalt parking area.

Credit SS 5.1a and b – Site Development: Protect and Restore Habitat

Beckstead – In this case, there is a savings most likely because we are using less paving. There are two or three different ways to figure this, in 5.1; a and b, it is a matter of looking at what plant materials are being used, and making sure it is native to the area. We are showing a savings of $24,000 on this point.

SS Credit 5.2: Site Development: Maximize Open Space

Beckstead – If more vegetation is needed to meet this requirement. I would suggest reducing paved area and deducting $1-$2 per square foot of paving reduction.

SS Credit 6.1: Storm Water Design: Quantity Control

Beckstead – There are many different ways to meet the requirements. In this case we have used some swales. We did not use a vegetated roof, but that would assist in quantity control as well. Total cost is $13,200.

SS Credit 6.2: Storm Water Design: Quality Control

Wennerstrom – If natural treatment can happen; the cost would be minimal because it would be incorporated into the landscape. In Colorado, the natural treatment would be the only way because stormwater has to be returned with in 24 hours per the local ordinance.

SS Credit 7.1: Heat Island Effect: Non-Roof

Wennerstrom – To use some other paving type could get into premiums in the $3-5 per square foot range. Shading may become more cost effective if the site warrants a good parking lot layout for this approach to be used. The trees may impact other credits because, in Colorado, you want to have temporary irrigation for more than one year on trees especially.

SS Credit 7.2: Heat Island Effect: Roof

Wennerstrom – If you use a vegetated roof and take cost into consideration the structure and the additional waterproofing, this credit becomes expensive. On some previous, project this has resulted in cost over $30 per square foot.

Beckstead – That is why I used $15 and it goes up from there for a vegetated roof. If the purpose of a vegetated roof satisfies other requirements, such as reduction of energy use, this may justify the additional costs.

SS Credit 8: Light Pollution Reduction

Beckstead – Light pollution reduction is more than cut-off fixtures on exterior lights. It has to do with interior lights also, so there are operating costs that can be saved by controlling when lights go off. Total costs will range in the $.35 per square foot or $25,000 for this project.

SS Credit 9: Safety and Risk Management

Haxton – What would you suggest as a rule-of-thumb cost of commissioning for equipment?

Baum – I don’t have a lot of data on that. On a recent lab building project we’re setting aside 5 percent of the cost of the equipment for certification, testing and calibration.

WATER EFFICIENCY

WE Credit 1.1 Water Efficient Landscaping: Reduce by 50 percent

Glen Beckstead – We are finding that water-efficient landscaping is one of the easiest credits to obtain. That may be only because we’re in Utah and we can change the type of grass seed to save 50 percent of the water. In most cases, we find this is very effective in reducing the water use by much more than 50 percent. This is a point that can save both construction costs and water. The irrigation system we put in can be smaller and less complex. In this project we show a $10,000 construction cost savings.

WE Credit 1.2: Water Efficient Landscaping: No Potable Water Use or No Irrigation

Wennerstrom – This credit is hard to achieve in Colorado because of the desert like climate. We can have this type of landscaping. However, it is only green when there is a lot of rain or in the spring, which is not always desirable by the owner/design team. Non-potable water is at a premium and typically used in parks and golf courses to make them green. If you are lucky enough to have non-potable water close by, the use would be encouraged.

WE Credit 2: Innovative Wastewater Technologies:

Wennerstrom – I have not attempted to look at this credit as the water they typically use is needed for dilution or their research. If the standard plumbing bathrooms are a large enough portion of the building, I would think this could be achieved with a small cost premium. It would all relate to the ratio of lab fixtures to other fixtures.

WE Credit 3.1 and 3.2: Water Use Reduction: 20 percent to 30 percent

Wennerstrom – To address all of these water efficiency requirements, including in the building, we’re almost always going with low-flow urinals. We’re almost always getting an innovation point because we do more water reduction in our buildings with no extra cost. It costs about $100 per fixture, which almost runs through all of these water use credits. They are easy to look at and easy to get without a great deal of cost.

ENERGY & ATMOSPHERE

EA Prerequisite 1: Fundamental Commissioning of the Building Energy Systems

Beckstead – Fundamental commissioning is absolutely essential in a lab and is a little more expensive than standard buildings. Commissioning is running about $1.25 to $1.75 per square foot.

McMahon – We benchmark it a little differently, I usually think about it as 1 to 2 percent of the costs of the systems to be commissioned. Relative to mechanical systems a reasonable assumption would be 1 ½ percent of the system costs.

EA Prerequisite 2: Minimum Energy Performance

Beckstead – Again it is one requirement that I very often do not include as a cost for LEED because most jurisdictions require a minimum energy use requirement. If costs need to be applied here they can be around $.80 per square foot but the payback is very short, approximately 2¼ years.

EA Prerequisite 3: Fundamental Refrigerant Management

Wennerstrom – This credit is not as big of an issue these days compared to the old refrigerant. Unless there is some process that needs the old refrigerant, I would think this cost is minimal if any cost should be used at all.

EA Credit 1: Optimize Energy Performance

Wennerstrom – This cost would be hard to pinpoint at the early stages. We have achieved efficiencies from upgrading the enclosure so we could downsize the equipment and adding recovery systems so we can have “free cooling”. I would use a cost of $1-3 per square foot for minimal enhancement for the first couple of points. I would think it will go up substantially from there in a laboratory project.

EA Credit 2: On-Site Renewable Energy

Beckstead – This one depends on how you get paid back for your power; what kind of power you’re going to generate.

McMahon – I was looking at the numbers that you have on the renewables. They look pretty aggressive to me. They’re all in a range of ten years and we have not seen that. We would typically see 25 years or higher.

Mathew – Clarification — Geoff is this including subsidies or excluding subsidies?

McMahon – Excluding subsidies. With Subsidies it can get better but on a dollar-to-dollar basis 25 to 30 years has been our experience.

EA Credit 3: Enhanced Commissioning

McMahon – I think the $.50 per square foot you have used is a good incremental cost of enhanced commissioning over standard commissioning.

EA Credit 5: Measurement & Verification

McMahon – The measurement and verification cost is a hard one because laboratory users and owners tend to be sophisticated users of control system so often the incremental costs of getting that point is not great, say $.15 to $.25 cents per square foot. On the other hand, when you get a user who is coming in on a very low level in terms of the level of instrumentation they are providing, that cost can get significantly higher.

EA Credit 6: Green Power

Wennerstrom – Typically we have found this to be an owner cost. It is not difficult to calculate this number; find the expected electrical load and purchase the amount of green power needed to get this point or (approximately $10,500 for this project).

EA Credit 7 Right-sizing Laboratory Equipment Loads

Baum – In this case not only the culture of the institution but the culture of the engineering group that we work with influences the savings. Sometimes we are able to get good factual knowledge about the operation of equipment, but often we only get projections of its importance on the people who use the equipment.

McMahon – I think the savings can be pretty significant in terms of first cost, especially when you’re talking about a biological lab that is load driven. If design loads are reduced from approximately 8 watts per square foot to around three, there is a significant decrease in capital cost associated with air handlers, ductwork, associated piping, etc.

Baum – We work with the engineers on the diversity factor they feel is reasonable for a particular application. Sometimes, for instance in regulatory testing laboratories or forensic laboratories, we are not allowed much diversity for plug loads. This is based on the 24/7 operation of those labs as well as the critical nature of those instruments on evidence analysis.

Beckstead – This point can save money in construction costs as well as long-term energy costs. In this project we are using a construction savings of about $4,000 and a yearly electrical savings of $18,000.

MATERIAL AND RESOURCES

MR Prerequisite 1: Storage & Collection of Recyclables

Beckstead – This point is usually achieved by giving people the opportunity to recycle by simple signage and collection points. This will seldom cost more than $5,000.

MR Credit 2: Construction Waste Management:

Wennerstrom – Now to the cost on waste management, we were just under a $1 per square foot. We diverted about 80 percent.

Beckstead – That seems correct. We used $.50 per square foot for 50 percent and $1.00 per square foot for 75 percent. If the site is located in a small jurisdiction, they may not have recycling. In larger jurisdictions, it may be either required or cost less.

MR Credit 2.1 – 2.2 Construction Waste Management: Divert 50 percent to 75 percent from Disposal

Beckstead – We find that diverting 50 percent is easy. When you start diverting 75 percent it is more difficult and may start costing money. The 50 percent diversion in most large towns will probably cost nothing.

Wennerstrom – As this becomes more mainstream, I feel the cost for this credit will be very minimal. At this point we usually have cost in verifying and keeping the recycle sorted properly. This could be a cost for one laborer for one-third to one-half of the duration of the project to manage and achieve these desired rates.

MR Credit 3.1 Material Reuse: 5 percent

Wennerstrom – Hard to do with new construction. If furniture is used, this may be achieved but it would be part of the FFE, which is not typically carried in the construction budget, if there are any premiums to be figured.

MR Credit 3.2 Material Reuse: 10 percent

Wennerstrom – This is very hard to achieve in a Laboratory Project.

MR Credit 4.1 and 4.2 Recycled Content 10 percent and 20 percent (post-consumer + ½ pre-consumer)

Beckstead – We find that 10 percent is fairly easy while 20 percent is very difficult to achieve. You have to really work at it and we are showing extra cost of about $.23 per square foot.

MR Credit 5.1 and 5.2 Regional Materials 10 percent to 20 percent Extracted, Processed & Manufactured Regionally

Beckstead – Regional Materials are the same way. It depends on where you are at and what type of building you are doing; 10 percent is not too hard, 20 percent is difficult. We have not done one yet where we can get this credit at reasonable costs. We feel that it would be around $1.75 per square foot to accomplish this credit because we are located in a portion of the country where distances are great.

MR Credit 6.1 Rapidly Renewable Materials

Beckstead – Rapidly renewable materials is changing every day because we’re moving away from some of the things that we have always thought of as rapidly renewable. We are using trees that are aged to be four inches instead of log size. Still the average cost is about $.75 per square foot.

MR Credit 7 Certified Wood

Kleiman – If we have a good case for certified wood, we try to convince the client to go for it — this is very hard. If I call a supplier they may tell me it is between 10 to 15 percent more to have the certified wood.

INDOOR ENVIRONMENTAL QUALITY

EQ Prerequisite 1 Minimum IAQ Performance

Beckstead – Minimum performance sometimes can be dropped out of the cost for LEED, because it is already something that you do based on local code requirements.

EQ Prerequisite 2 Environmental Tobacco Smoke (ETS) Control

Beckstead – Environmental Tobacco Smoke – Something you should already do, but I do show a cost of about $900 to cover signage. If it is a state law, it is not a LEED cost.

EQ Prerequisite 3 Laboratory Ventilation

Mathew – That prerequisite actually has to do with meeting the minimum requirements in ANSI Z 9.5. As I recall, most laboratories would be meeting that anyway. We have cited certain parts that are relevant — mostly things related are room pressure control, which again you mostly do in laboratories.

EQ Credit 1: Outdoor Air Delivery Monitoring

Wennerstrom – Because most laboratories we build need a large volume of outside air, the monitoring is only a small part of this credit. Control contractors typically will charge around $2,500 per monitoring station. You could figure some parameters based on this cost for figuring a parameter in EarlyEco.

EQ Credit 3.1: Construction IAQ Management Plan: During Construction

Wennerstrom – Very little cost in a laboratory building as the contractors need to achieve certain standards which are close if not better than LEED standards.

EQ Credit 3.2: Construction IAQ Management Plan: Before Occupancy

Beckstead – The cost is minimal but includes some additional cleaning and changing merv 13 filters at the end of construction. We have allowed $7,200 dollars for this option.

Wennerstrom – The two-week flush is typically hard because they need the buildings to start their research. The cost for the second option in this credit would be born out of spending some energy and the cost for filters to do the early flush before people arrive. This energy cost would be born by the owner and they should be made aware of this expense.

EQ Credit 4.1: Low-Emitting Materials-Adhesives & Sealants

Beckstead – Low-emitting materials and sealants is getting to be a zero cost. We don’t write any of our specifications without using these products. I leave a little cost in there to take care of a few things that might come up since you need a particular kind of sealant in a laboratory.

EQ Credit 4.2: Low-Emitting Materials: Paints and Coatings

Wennerstrom – There is a small cost here and it is becoming more commonplace. This will become an issue if there are highly corrosive areas or BSL 3 areas that cannot be coated with standard-type products.

EQ Credit 4.3: Low-Emitting Materials: Carpet Systems

Wennerstrom – This credit is becoming more standard and should not be a cost increase to the project.

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

Beckstead – There is a cost in there, and it can be a big cost. We are showing about $2.00 per square foot.

EQ Credit 5: Indoor Chemical and Pollutant Source Control

Wennerstrom – This should not be much of a cost because in the labs we have completed this is already accounted for by codes or the owner’s preferences.

EQ Credit 6.1 Controllability of Systems - Lighting

Beckstead – Controllability of lighting systems is one of the big questions that still need to be investigated further depending on the application. We find this to be an added cost of about $.25 per square foot.

EQ Credit 6.2 Controllability of Systems - Thermal

McMahon – The cost of this item can be very high. It can involve the addition of a large number of control zones. I believe it will be higher than the amount you have indicated.

Beckstead – If you take the controllability of systems and thermal comfort design at $250,000 that is a significant $3.50 per square foot.

McMahon – The savings are often overstated, but there are other reasons to do this. The quality of the environment can be significantly enhanced if it is done correctly.

EQ Credit 7.1 Thermal Comfort: Design

Wennerstrom – This credit has some synergy with the energy savings credit. If you take care of the enclosure in the energy savings credit, the additional air terminals/control points could be substantial if everyone gets separate control. We usually figure this to be in the neighborhood of $2,500 to $4,000 per control point depending on building layout and control needs.

EQ Credit 7.2 Thermal Comfort Verification

Wennerstrom – This should be a fairly easy process the design team could incur to achieve this point from a survey standpoint. I would put the cost on the design team side. If design and construction meets the desired design no corrective action is typically needed.

EQ Credit 8.1 and 8.2 Daylighting & Views: Daylighting for 75 percent and 90 percent of Spaces

Carmichael – I think this is a challenging credit not only in terms of meeting the intent of the credit, which is to improve design conditions, but it is also a really hard one to quantify the cost of it. I think the 2 percent is a reasonable metric to work within, and we encourage it to be done with a bigger picture intention in mind — not just the LEED credit. The other part is looking at the larger impact those measures are having. By utilizing daylight in the space, you are not only reducing the number of electric light fixtures that you need, but you are also reducing the internal heat gain you are contributing to the space and you might be able to downsize or eliminate certain systems.

EQ Credit 9.1 Indoor Environmental Safety: Contaminant Device Commissioning

Mathew – I have heard a number around $500 per hood for 110 Commissioning (9.1).

EQ Credit 9.2 Indoor Environmental Safety: Protection and Notification Systems

Beckstead – Protection and Notification Systems is again safety protection and the way I have analyzed this is to make sure you have alarms to tell someone something is going wrong. For the lab building we are looking at it would be around $.25 per square foot.

INNOVATION & DESIGN PROCESS

ID Credit 1 Innovation in Design: Facility Used as a Teaching Tool

Kleiman – Something that we see commonly now in innovation of design, especially for academic labs, is LEED as a Teaching Facility, as a teaching tool. It is not just for the people who work and do research in the labs, also for the public or when they have big events. That is something we try to integrate into our projects.

Baum – We have used two approaches. We have used electronic information kiosks and learning walls, which displays a lot of information. Another is providing duplicate controls of devices that show the monitors of the building so that at any one time a student can look over on the display doors to see how many CFM is being used or BTUH or Watts or whatever.

ID Credit 2 Innovation in Design:

Carmichael – Beyond some of the standard ID credits: green housekeeping, environmental education, exemplary performance, there are a few interesting examples in the LEED for Labs system. Those include mini- environments, displacement ventilation, optimized utility services, flexibility and modularity, and design for catastrophic events.

Cost Summary

Beckstead – LEED for Laboratories is different than what you have done in past because it is not under NC.

Haxton – As you can see on the spreadsheet (see attached spreadsheet) we have the building cost at the top, and the square footage to remind us of the building we are dealing with. We then have the summary for the different categories and certification. We take two extra credits to be on the safe side, and pursue those 28 credits at a cost of $708,782. But the savings per year was up at $330,804 category, which gives us a payback of 2.14 years. I would like to have your reactions to these numbers as to whether these are reasonable or not and what are your experiences?

Baum – Our experience is that these initiatives had to come in generally within a five-year payback.

Kleiman – For the project we have in Scottsdale, there had to be a payback in five years.

Haxton – The Gold payback was shown at 3.65 years and the Platinum was at 5.29 years. Even the Platinum seems to be a very rational approach to pursue for this laboratory we were talking about.

Carmichael – None of these seem way off in my experience. It is probably in the range and we have worked on many projects that have been non-lab that have achieved the Platinum with no additional cost. I know that the lab is different. I think in general I appreciate what is trying to be done. I think it is a great start for providing this type of information early in the design from people who really can apply this tool and know how to integrate it into the larger context of design.

Wennerstrom – One of the main things I see benefit from EarlyEco is it creates discussion early on in the process. We all recognize that the results are conceptual, but at least you can identify the low hanging fruit and set a realistic goal for the project. The design team and construction team can monitor the goal through pre-construction, which is really what an owner ultimately wants to know. With owner, design and construction team members monitoring cost and design to achieve a common LEED strategy goal will eliminate a common disconnect from different assumptions early on in the process. When the assumptions do not align between all team members then pre-construction activities don’t achieve the desired results from a LEED/project standpoint. Setting expectations early using this tool with the discussion points included in the EarlyEco are very important and I can see contractors working in conjunction with the results to back up the ultimate design.

Haxton – What we do is use this EarlyEco process that integrates the contractor, consultants, and client in the decision making process. We try to define their sustainability and budget goals. That is where it starts, then we narrow it down to allow owners to see what the cost ramifications are for their decisions.

Roundtable Summary

The discussion of the laboratory roundtable is to be a starting point for a greater dialogue about sustainable laboratory design practices and the related costs. The information in the discussion is for a special building on a special site with an 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 building or site. Each site is very special and the analysis and costs are specific to that particular site. When dealing with laboratories, sustainable architecture, cost analysis, and specialized engineering systems, seek professionals with experience in each and every aspect of the building you are working with.

Further Study

MHTN has further studies that are planned to define the carbon footprint information on each credit. This will help us analyze not only the least expensive credits, the least expensive credits with the highest sustainability, but also be able to factor in the credits that affect a minimized carbon footprint with the lowest cost. Another area of special interest i