5.6 Design and Construct Only the Greenest, Most Energy Efficient New Buildings
- 5.6.1 LEED Green Building Rating System
- 5.6.2 Labs21
- 5.6.3 Green Design Strategies and Measures
- 5.6.4 Green Design Process
- 5.6.5 LEED Silver is Not Good Enough!
- 5.6.6 Addressing the Cost of Green Design
- 5.6.7 Some Potential Achilles Heels -- Ventilation, Lighting, Windows
- 5.6.8 Green Building Resources and Under-Resourced Higher Education Institutions
5.6.1 LEED Green Building Rating System
The U.S. Green Building Council has done a great service by advancing the concept of green buildings through its consensus-based LEED green building rating system. LEED stands for “Leadership in Energy and Environmental Design.” A number of LEED certification systems have been developed. The one we are most concerned with here is LEED for New Construction (LEED-NC).
To be LEED certified, buildings must achieve a variety of prerequisites in these categories:
- Sustainable Sites
- Water Efficiency
- Energy and Atmosphere
- Materials and Resources
- Indoor Environmental Quality
- Innovation and Design Process
LEED points are earned for achieving various credits in each of these categories. Depending on the number of credit points reached, a LEED building will be either LEED Certified (26-32 points), LEED Silver (33-38 points), LEED Gold (39-51 points), or LEED Platinum(52-69 points).
Examples of campus green buildings are available from the ACUPCC and AASHE. AASHE also maintains a list of campus green building policies. The U.S. Green Building Council’s Green Campus Campaign also provides helpful resources.
Laboratory buildings tend to be the most energy intensive and energy wasteful buildings on campus because of their 100% outside air ventilation systems, stringent temperature and humidity control requirements, 24/7 operation, and the energy consumed by environmental chambers, water purification systems, ovens, and other research equipment. Making new labs as energy efficient as possible is very important because their energy cost and environmental impacts are so high.
The U.S. Green Building Council has deferred to Labs21, a federal program sponsored by the U.S. Environmental Protection Agency (EPA) and Department of Energy (DOE), for establishing guidelines for green design of energy efficient laboratory buildings. Labs21 builds on the LEED green building rating system, adding prerequisites and credits pertaining to health and safety, fume hood energy use, and plug loads.
To improve lab building design, Lab21 provides technical bulletins and best practice guides on numerous subjects including:
- Optimizing Laboratory Ventilation Rates
- Modular Boiler Systems in Laboratory Facilities
- Metrics and Benchmarks for Energy Efficiency in Laboratories
- Manifolding Laboratory Exhaust Systems
- Retro-Commissioning Laboratories for Energy Efficiency
- Efficient Electric Lighting in Laboratories
- Minimizing Reheat Energy Use in Laboratories
- Water Efficiency Guide for Laboratories
- Daylighting in Laboratories
- Energy Recovery for Ventilation Air in Laboratories
- On-Site Power Systems for Laboratories
5.6.3 Green Design Strategies and Measures
There are hundreds of green design strategies and measures. These general principles are among the most important:
- Build small if at all
- Optimize site selection in order to preserve green space and minimize transportation impacts
- Orient building to take maximum advantage of sunlight and micro-climate
- Use energy as efficiently as possible
- Maximize the use of renewable energy
- Use water as efficiently as possible
- Minimize waste water and run-off
- Minimize materials impacts by using green products
- Design for a healthy indoor environment
Green design strategies, measures, products, specs, guidelines and examples can be found at these websites and others:
- American Institute of Architects, Committee on the Environment (COTE)
- Campus Green Bulder
- Collaborative for High Performance Schools
- Daylighting Collaborative
- Energy Star for Higher Education
- Green Building Resource Guide
- High Performance Building Database
- Net Zero Energy Buildings
- NYC High Performance Building Guidelines
- Oikos: Green Building Source
- Sustainable Buildings Industry Council
- UB High Performance Building Guidelines
- US EPA Green Buildings
- US Green Building Council
- Whole Building Design Guide
5.6.4 Green Design Process
The nature of the design process itself is critical. It is important to hire a design consultant with a proven track record in super-efficient green buildings that are not budget busters. Smart design can produce very green buildings with a low premium cost. The process should begin with the consultant leading a green design charrette with all stakeholders in order to establish strong low-carbon green goals for the new building.
It is important to avoid what can be called the “LEED checklist approach” wherein the LEED checklist is cherry-picked to find the cheapest, easiest way to rack up enough points to achieve a LEED rating. Institutions looking to reduce their emissions are not looking for a conventional building which just happens to have enough points to earn a plaque. Your goal should be a thoroughly sustainable design that prioritizes and maximizes energy efficiency and reliance on carbon-free solar and other renewable energy sources.
Many a good design has foundered when the inevitable building budget crisis occurs. What typically happens when the design goes over budget (and this can happen in spades when the original budget was inadequate) is that the energy conservation and sustainable design features are sacrificed first. How to prevent that? One strategy is to anticipate the building budget crisis and already identify ways to bring extra funding into the project. Maybe a wealthy alumnus or alumna will want to make a special contribution to ensure that this project breaks new ground in efficiency and the use of renewable energy. You can also argue that if a measure is on the chopping block – like for example a heat recovery system – and it could be cost effectively retrofitted through a performance contract after the building is constructed, then your school should borrow the money for this measure now and install it as part of new construction when that installation will be cheaper and easier.
It also helps to have strong backers on and off campus demanding an unwavering commitment to super energy efficient green design. While you may not get the kind of support you want from faculty (who may be distracted by the demands of teaching and research) or from professional staff (who may be muted by bureaucratic constraints), your ace in the hole are students. They are free to speak out and may be inclined to raise their voices on behalf of a super efficient building that really makes an environmental statement. Of course, it also helps to remind your administration that a failure to max out on new building energy efficiency will make it that much more difficult and costly to keep your climate goals.
5.6.5 LEED Silver is Not Good Enough!
If your campus is proceeding with new construction and is committed to achieving significant GHG emissions reductions, achieving LEED certification or a LEED Silver rating is inadequate. It would be better from an environmental and carbon-reduction perspective if your goal was LEED Gold or Platinum with a maximum number of LEED credit points that reduce the energy use and carbon footprint of the project. While many LEED credits can affect fossil fuel use and the carbon footprint of a new building, here are the credits to focus on:
Sustainable Sites (SS)
- SS Credit 1 – Site Selection (Note: the criteria for this credit do not directly address commuting distances, but proper siting – near other development and close to public transit -- is critical for minimizing transportation-related carbon footprint)
- SS Credit 2 – Develop Density and Community Connectivity (same comment as above)
- SS Credit 4.1 – Alternative Transportation: Public Transportation Access
Energy and Atmosphere (EA)
- EA Credit 1 – Optimize Energy Performance (maximize these points; up to 10 are possible – go for 8 to 10!)
- EA Credit 2 – On-Site Renewable Energy (maximize these points; go for all 3!)
- EA Credit 6 – Green Power
The above LEED New Construction credits are most important from the point of view of emissions reductions because they address the major elements of most campuses’ carbon footprints as revealed by GHG inventories, i.e. energy and transportation impacts.
Of course, other LEED credits can also help reduce the carbon footprint of a new building, even if those emissions reductions are not captured by the GHG inventory process. For example, reduced water use or waste water production will reduce energy use regionally and thus reduce GHG emissions (as well as produce other environmental benefits). New construction that involves reusing existing buildings or maximizing the use of certain types of green building materials and products will reduce embodied energy and thus reduce carbon emissions – albeit globally. Since our ultimate goal is saving the planet, pursuing these mitigation strategies is important even if your GHG inventory tool will not give you credit for the reductions.
5.6.6 Addressing the Cost of Green Design
Green design is generally believed to add cost to new construction projects. This premium, however, is often exaggerated. It is possible to design and construct green buildings with little or no extra cost. That becomes more challenging as the bar is raised for aggressively green, super-efficient buildings.
There are a variety of ways of eliminating or minimizing extra costs for green buildings. For example, in many regions, state or utility company incentives are available to cover costs associated with green design services or reducing the cost of specific energy efficiency and renewable energy technologies and products. Hiring an experienced green design firm can also keep costs in line. Moreover, it is possible to “tunnel through the cost barrier” and achieve big savings for less than the costs of small ones.
Tunneling through the cost-barrier, a concept popularized by the Rocky Mountain Institute, requires a whole building design approach that takes advantage of the interaction of building systems. By optimizing some systems (e.g. insulation), other systems can shrink or be eliminated (e.g. heating systems) – thus offsetting the optimization costs. For more information, see Chapter 6 of Natural Capitalism by Paul Hawken, Amory B. Lovins, and L. Hunter Lovins (1999).
When discussing the cost of green buildings, it is important to distinguish between first costs (i.e. design and construction costs) and lifecycle costs. Life cycle costs include first costs plus the costs to operate and maintain a building for its lifespan – which in the case of a campus building may be 100 years. Additional increments of first cost incurred to make a building much more energy efficient may pay for themselves many times over in energy and carbon offset savings over the life of the building. Payback, in the conventional sense, should become less important because a college or university will own and operate the buildings it constructs for such a long time horizon.
For more information on the cost of green buildings, see USGBC's list of research publications on the cost analysis of whole buildings.
5.6.7 Some Potential Achilles Heels -- Ventilation, Lighting, Windows
There are a few places where green design goals may conflict. Here are two examples – ventilation and lighting -- plus a few comments about the tricky subject of windows and green design.
Ventilation pros and cons
Care should be taken when considering LEED Environmental Quality (EQ) Credit 2 – Increased Ventilation. Higher ventilation rates typically increase building energy consumption and thus GHG emissions because they require more fan energy and can substantially increase heating and cooling loads. But increased ventilation is a good thing from an indoor environmental health perspective, right? Well, yes, but it comes at a price and its benefit can be minimal.
Building codes mandate that new buildings be designed for ventilation rates appropriate for maximum occupancy, a condition which almost never exists. Thus, it is arguable that a building whose ventilation rate is merely code compliant is already over-ventilated the vast majority of the time and that providing ventilation over and above code requirements (as envisioned by EQ Credit 2) may provide little or no health benefit while substantially increasing energy consumption and GHG emissions.
There are ways to increase ventilation while minimizing energy and GHG penalties -- for example, by installing heat recovery or using variable speed drives and air quality sensors to modulate air flows so that air volume (measured in terms of cfm or cubic feet of outside air per minute) is appropriate to actual occupancy. These technologies are steps in the right direction and should be used extensively but the net effect of increased ventilation is almost always greater energy use and thus a greater carbon footprint.
Direct and Indirect Lighting
Green designs tend to use indirect lighting which eliminates glare and lighting hot spots and may produce more comfortable lighting and thus increase productivity – all important pluses. However, lighting fixtures and designs of this type may be more expensive and less energy efficient in providing illumination on the work surface. As a result indirect lighting may drive material and energy costs up and with them the carbon footprint of building lighting systems.
There are number of ways to cope with the potential downside of indirect lighting. The first is to avoid indirect lighting and instead use conventional direct lighting systems, i.e. recessed troffers. These provide good light and, especially if equipped with high efficiency lenses, can be very efficient.
Another approach is to use indirect lighting fixtures sparingly or to provide a low level of background lighting and then rely on efficient task lighting to put light on the work surface. Note that overall lower foot-candle levels may be acceptable not only because of the availability of task lighting but also because the light quality of new fluorescent lamps (as measured by CRI or color rendering index) is far superior to older fluorescent bulbs and is perceived by the human eye as brighter than foot-candle measurements would lead one to expect. It makes sense to take advantage of this and thus to design for lower foot-candle levels.
Instead of prescribing in detail the kinds of lighting design and fixtures you want, you can give more latitude and require the designer to meet an aggressive performance standard. For example, you could require a building-wide average lighting wattage density of no more than 0.75 – 1.0 watt per square foot – erring on the low side – and of course taking into account the benefits of daylighting.
Sensible, Efficient Use of Glass and Windows
It is common for new buildings, irrespective of LEED rating, to have lots of glass. Large windows, glass walls, and exciting atria can produce beautiful daylit spaces. But glass, unless properly specified and judiciously used, can also have a large energy and GHG penalty.
Daylighting designs should be computer-modeled to ensure that the electric lighting savings they produce are much greater than the additional heating or cooling costs they impose. Also, as obvious as this is, it deserves re-stating: not all windows are equal in their performance. There is a tendency to think that if windows are Energy Star-compliant that is sufficient, but the Energy Star standard for windows is outdated and profoundly inadequate.
Genuine high performance windows should be selected – and in cold winter weather climates that means triple glazed windows with double low-e coatings with center of glass U-values of 0.15 or better. Where south-facing windows are serving a passive solar heating function during the heating season, they should be specified to have as high a Solar Heat Gain Coefficient as possible -- otherwise they will block sunlight and substantially reduce insolation or solar gain. Architectural shading is required for south-facing windows to block direct summer sun entering windows, exacerbating cooling loads.
If you opt for operable windows, an indoor environmental quality benefit, a system should be established so that occupants know when they can open windows and when they need to be shut. Such a system would evaluate the enthalpy or heat content of indoor vs. outdoor air to determine when there is an energy benefit or penalty associated with open windows. Windows can be interlocked with HVAC systems so that heating and cooling is shut off when windows are open.
5.6.8 Green Building Resources and Under-Resourced Higher Education Institutions
The Campus Green Builder is an initiative by the Advancing Green Building program at Second Nature. The site was launched on November 2nd 2009 and is a repertoire of resources for those with an interest in green building development either as a hobby or out of necessity.
Community colleges, Historically Black Colleges and Universities, tribal colleges, Hispanic-serving institutions and other under-resourced institutions are often at a disadvantage due to the lack of funds, lack of expertise and lack of exposure to readily available resources. With technical, financial, educational, various other resources and discounted memberships, Campus Green Builder aims to provide its audience with a central location where they can start acquiring the knowledge and tools to become familiar with sustainable development.
Though relevant to higher education as a whole, Campus Green Builder is particularly beneficial for under-resourced institutions considering building green on their campus but do not know where to start and are not aware of the assistance available in their regions and states. For example, under the financial section of the site an individual in Alabama can sort for state funding and find out that “Tennessee Valley Authority (TVA) offers a production-based incentive program for the installation of solar photovoltaics (PV), wind, low-impact hydropower, and biomass to customers of the Tennessee Valley.”
The Campus Green Builder provides hundreds of links to green building-related web sites, directories of experts, and resources for training and funding opportunities. This web portal is also excellent for accessing green building related news, events and networking resources. Finding an expert in your region to discuss your plans or assess green building potential on your campus is now easier than before by going to the many green expert directories on the Campus Green Builder website. The hope is that this web portal will be the stepping stone, a starting point in other words, to explore various opportunities through not only resources but also case studies of under-resourced institutions and networking with other higher education individuals.
Did you know the Los Angeles Community College District is taking nine of its colleges off the grid? How are they planning to do this? Visit the East L.A. College Case Study on the Campus Green Builder to find out!
To read the news release regarding the Campus Green Builder launch, click here.
For more information about the Advancing Green Building program, contact Program Director Amy Seif Hattan or Program Manager Ashka Naik.
For information about Advancing Green Building internship opportunities for graduate students and college seniors, please visit the Employment Opportunities section.
This guide was produced with financial support from the American College & Univerisity Presidents Climate Commitment.