By Alex Wilson
Kroon Hall at Yale University embodies many green building priorities, including 60% energy savings, harvested rainwater for toilets, infill development of a brownfield site, and use of FSC-certified wood.
Rarely can we do everything we want with a green building project—particularly in today’s constrained economy. When we are forced to choose, where will our efforts make the most difference in improving the environmental and health performance of our built environments?
We last took a comprehensive look at these questions in
Environmental Building News
way back in September 1995. A lot has changed in 15 years: global climate change has gained greater recognition as a concern; phthalate plasticizers, halogenated flame retardants, bisphenol-A, and other chemicals have emerged as health concerns; the U.S. Green Building Council emerged as a major player and launched the LEED Rating System; and green building has edged its way into the mainstream vocabulary.
This article takes a new look at how we should choose green building priorities. We’ll look at priorities from a few different angles, including:
• priorities for the design and construction process;
• priority outcomes determined during design and construction;
• priorities relating to operation;
• and priorities for the green building movement, detailing what we need to do to make our efforts more successful.
we use in designing and building have a tremendous impact on what we create. The priorities below, starting roughly with the most important, relate to how we go about our work as designers and builders.
We enter into the planning and design process with a lot of assumptions: what we’re going to build, where, and so on. Question these notions:
• That a new building is really needed.
• That it’s okay to be developing a greenfield (undeveloped) site—if that’s on the table.
• With homes, that 2,500–3,500 square feet is really needed. Can we meet the needs with less space?
• That green has to cost more. By shrinking the building footprint, clustering buildings, more creatively handling stormwater, or through many other options, first-cost savings might well be achievable.
• That first-cost should be the driver of decision-making; we need to instill
into building design and construction, factoring in issues such as operating cost and durability.
We may end up back at the starting point, but raising issues like these could inspire discussions that result in a better, greener building.
Integrated design is at the heart of green building. By including mechanical engineers in discussions about building form, fenestration, orientation, and energy detailing, opportunities for better design will likely emerge. With commercial buildings, operations and maintenance personnel can offer invaluable perspectives on design. Enlightened civil engineers and landscape architects can provide suggestions about siting that can save tens or hundreds of thousands of dollars on stormwater conveyance, sitework, and buried utilities. Not only does integrated design usually result in a better building, it also often reduces construction costs. This should be a requirement for most design teams. For more on this issue, including associated challenges and new tools, see “Integrated Design Meets the Real World” in the May 2010
Experts tell us that significant changes are needed in the buildings we create. The Cascadia Green Building Council (and now the International Living Future Institute) has articulated this better than anyone through the Living Building Challenge—arguing that we not only need net-zero-energy buildings but also need to aggressively address water, toxic chemicals, land-use, and other key priorities. While net-zero-energy may not make sense for every project, every architect would benefit from the process of actually designing such a building and seeing it through to completion (see “The Problem with Net-Zero Buildings (and the Case for Net-Zero Neighborhoods),”
EBN Aug. 2010
Try to go a little further with each project, as you and others on the design team, along with contractors, gain increased experience and comfort with green design practices.
While the leading edge of green design needs to be continually pushed forward, many basic greening strategies should be incorporated into standard practice. Energy modeling, for example, should be a standard part of design today, and rigorous targets for energy performance should also be applied to all projects. WaterSense fixtures can become a default specification. Work with consultants to change standard contract language so that they are obligated to participate in creating high-performance solutions.
LEED Gold certification of the EcoTrust Building in Portland, Oregon provides third-party verification of the building’s green features.
Third-party certification of buildings—through Energy Star, LEED, Passive House, the Living Building Challenge, or other programs—can make a significant difference relative to environmental and health performance. These programs offer specific targets for energy performance and, with broader programs like LEED and the Living Building Challenge, other aspects of environmental and health performance. The more rigorous certification programs provide outside verification that certain standards have been met, offering building owners confidence that their desires are being achieved.
Third-party certification of buildings should be a high priority for design teams with relatively little experience in low-energy green buildings. Get a few certified buildings under your belt before you consider backing off and saving certification fees for measures that improve building performance directly.
Third-party certification of products is an important way to evaluate claims by manufacturers and gain confidence that products you specify will achieve the environmental performance you are seeking. When hardwood flooring carries the Forest Stewardship Council (FSC) label, for example, you can be confident that the wood was harvested from well-managed forests. Be aware, though, that some certification systems are far more rigorous than others—some are little more than green marketing schemes created by industry interests. BuildingGreen (publisher of
) has just released a new report on product certification that will help specifiers untangle the complex web of product certifications and understand which programs are rigorous.
In addition to third-party certification of products—and especially when manufacturers have not gone through the certification process—look for
. Manufacturers should divulge what’s in their products, particularly with chemical-based products like paints and adhesives. Unwillingness to say what’s in a product should raise suspicions that the manufacturer has something to hide.
Green design and green building practices are complex—really complex. Creating a net-zero-energy, carbon-neutral building while ensuring that there won’t be moisture problems that threaten its durability or offgassing from materials that could make building occupants sick requires an investment in education.
Design and construction firms should commit to ongoing education of all employees. The continuing education requirements from The American Institute of Architects and the Green Building Certification Institute provide an incentive for this sort of learning, but that shouldn’t be a limitation. There are lots of useful resources, from books to workshops, that aren’t registered for continuing education credits. When you don’t have in-house expertise needed to institute a new strategy, bring in an outside expert for that project, and learn from that specialist to build in-house expertise.
There are many ways that design and construction firms can reduce their own environmental impacts.
• Travel less, by relying on teleconferencing, for example.
• Provide incentives for employees to be greener—public transit vouchers to minimize commuting by car, rewards for bicycle or carpool commuting, work-at-home options, prizes for the best company greening recommendations, and so forth.
• Provide energy-saving laptop computers in place of desktop models—and encourage less use of individual offices, reducing square footage needs.
• Avoid unnecessary printing, using digital documentation to reduce the need.
• Implement a comprehensive recycling program.
• Make sure your office energy, environmental, and health performance is as strong as possible. If you lease space, work with your landlord to make it greener.
• Minimize construction impacts through more responsible jobsite practices and better specifications regarding sitework.
While process is important, it is the
that most of us focus on relative to green buildings. The ten priorities below cover the outcomes we try to achieve in a building—the aspects of that project that are determined by the time the building is completed and occupied.
Sophisticated exterior shading at the David Brower Building in Berkeley, California, helps to minimize unwanted solar heat gain.
Arguably the most important priority in creating a building is to minimize the energy required to operate it. In skin-dominated buildings (homes and smaller commercial buildings), the building enclosure (walls, roof, and foundation) usually plays the most important role in determining how much energy will be required for operation. Key measures that fall under this category include:
• using high levels of insulation and airtight construction with efficient ventilation;
• installing high-performance windows—in colder parts of the country, triple-glazed with two low-e coatings; and
• designing passive measures to minimize unwanted heat gain—for example, careful attention to building orientation and fenestration, glazings tuned by orientation (lower solar-heat-gain-coefficient glass on west- and east-facing windows), and window treatments to control solar heat gain.
A green building should be designed to employ passive measures first—passive solar heating, daylighting, natural ventilation—with highly efficient active systems specified as needed to serve demand not satisfied by those passive systems. By doing a better job in reducing heating and cooling loads (priority one, above), we can rely less on either passive or active systems to maintain comfort.
Convenient bicycle storage at the EcoTrust Building in Portland, Oregon, makes it easy for employees to commute to work by bike.
It surprises a lot of people to learn that it often takes as much or more energy to get people to and from a building than the building itself uses. This was the finding—with office buildings—of a September 2007
article, “Driving the Green Buildings: The Transportation Energy Intensity of Buildings.” For an average office building in the U.S., 30% more energy is used for commuting than for building operations, according to our findings, while a building built to the ASHRAE 90.1-2004 standard requires more than twice as much energy for commuting as for operations.
This means that it is very important to address location and access to alternative forms of transportation in creating green buildings—especially for projects in suburban locations. We need to embrace density, mixed-use development patterns, and access to networks of walkways, bike paths, and bike lanes. Larger development projects should include internal bicycle and pedestrian paths as well as connections to outside trail networks and public transit stops.
is inherently green from the standpoint of transportation energy intensity. Urban infill projects are almost always superior to suburban and rural greenfield sites when it comes to low transportation energy use.
Some experts warn that water will be a greater global challenge than energy over the coming decades. One of our top priorities in green building should be to reduce water use, both by specifying water-saving plumbing fixtures and appliances indoors, and by designing landscapes outdoors that will require little if any water. In some areas, reducing water use should be the top priority, trumping even energy savings. Note that reducing water use also saves energy (see “The Water-Energy Connection,”
EBN Oct. 2010
A green building should be a healthy building. It shouldn’t grow mold or release chemicals or build up high levels of carbon dioxide. With use of daylighting, views to the outdoors, and indoor plantings, we can create buildings that not only keep people healthy but also create spaces that are very satisfying to spend time in. There is some evidence that this can lead to higher productivity in the workplace, improved learning in the classroom, faster recovery in hospitals, and reduced stress across-the-board (see “Productivity and Green Building,”
EBN Oct. 2004
). Here are a few specific strategies for the design and construction phase of buildings.
• Provide detailing that will avoid moisture problems and mold growth—for example, deep roof overhangs, surface grade sloping away from the building, proper flashing, and rainscreen detailing to provide a capillary break at walls.
• Specify track-off mats for entryways. This is one of the easiest ways to cut down on pollutants and moisture being tracked into a building. (See “Keeping Pollutants Out: Entryway Design for Green Buildings,”
EBN Oct. 2001
• Specify zero-VOC or low-VOC paints, sealants, and other materials with chemical constituents.
• Avoid materials containing halogenated flame retardants, bisphenol-A (BPA), phthalate plasticizers, and added urea formaldehyde. (For more on evaluating chemicals of concern, see “Chemistry for Designers: Understanding Hazards in Building Products,”
EBN Mar. 2010
• Provide quality ventilation systems that will deliver appropriate levels of fresh air throughout a building.
• Provide daylighting and connections to the outdoors. (See “Biophilia in Practice: Buildings that Connect People with Nature,”
EBN July 2006
Larger buildings take more materials to build and require more energy to operate. Work on programming with clients and try to design efficient spaces and minimize building square footage. This is particularly important with homes, where there is rampant “supersizing”—driven both by the quest for status among homeowners and by the real estate industry, which continues to push large homes. Try to build to standard dimensions to use materials most efficiently and minimize construction waste. Look for “structure-as-finish” opportunities, such as a polished concrete floor that obviates the need for a separate floor surface on top of the slab.
A green building should last a long time. Building science expert Joseph Lstiburek, P.Eng. argues that a properly designed and built home today should last 1,000 years. From an aesthetic standpoint, seek “timeless architecture” rather than catering to short-term fads. With both homes and commercial buildings, an important part of designing for durability is creating buildings that can easily be adapted as needs change. In his book
How Buildings Learn
, Stewart Brand suggests that different layers in buildings should be designed for different lifespans. Following this guidance, a good rule might be to create structural layers that will last hundreds of years; exterior sidings and interior finish materials that will last 50–100 years; and mechanical systems that will last 20–50 years. Design for relatively easy replacement of these more ephemeral layers.
An important part of durable design is preventing moisture entry and damage—the leading cause of damage in most buildings. The same measures that avoid decay in wood-framed buildings and corrosion in metal buildings also help to ensure a healthy indoor environment (see specifics under Priority Five, above). Part of ensuring durability is renovating older buildings rather than building new. Dramatically reducing the energy consumption of existing buildings makes them relevant to future resource constraints and what are likely to become overriding desires to minimize carbon emissions.
Of all the impacts we’re having on the Earth—from air and water pollution to ozone depletion and global climate change—species extinction (loss of biodiversity) is likely to be the most permanent. Ecologists point out that it can take hundreds of thousands or even millions of years of evolution to refill ecological niches that are being vacated through the epidemic of species extinctions occurring today.
There are various indirect ways in which green design and material selection can help to protect biodiversity—by building smaller (to use less raw materials), by creating lower-energy buildings (to reduce the need for fossil fuel extraction and to slow climate change), and by using only tropical hardwoods that have been certified through FSC standards. But there are also direct ways our development can protect biodiversity. Such measures include building on the edge of a lot and keeping much of the site undeveloped, restoring damaged ecosystems around our buildings through removal of invasive species and restoration of natural stream flows, replacing turf with native plantings, controlling light pollution (especially in coastal areas), and practicing “bird-friendly” design to minimize bird collisions into glass. By reusing buildings, we also reduce pressure on undeveloped, greenfield sites with healthy ecosystems.
We can also help building occupants appreciate nature by designing fenestration that looks out on natural areas and providing outdoor living (and working) spaces. A good starting point with these efforts is to involve a landscape architect or ecologist in the planning process with a development project—particularly one involving a significant land area.
Recycled-content products and biobased building materials are considered by many to be at the heart of green building, but issues like how we assemble materials into a building to save energy or keep the building healthy, and where we put that building, are significantly higher priorities in most cases. While some building materials are considered green by virtue of what they are made of or how they are produced, others are green because of what they do: reducing water or energy use, for example, or helping to ensure good indoor air quality. These latter examples are addressed through other priorities. Much more information on green building materials can be found in BuildingGreen’s
Even if today we were to magically turn off the engine of climate change—the anthropogenic emissions of carbon dioxide and other greenhouse gases—climate scientists tell us that significant climate change would still occur based on greenhouse gases already in the atmosphere. And, clearly, those emissions are not likely to be curtailed anytime soon. For this reason, we need to be designing and building homes and commercial buildings today that will continue to perform well in the changing conditions that accompany climate change: increasing temperatures, changing precipitation patterns, more intense storms, and rising sea levels.
We need to design buildings based on higher summer design temperatures and do a better job at minimizing cooling loads, we need to plan for higher flood elevations, we need to build to more rigorous storm standards (such as the Miami-Dade County Hurricane Code), and we need to create buildings that will maintain livable conditions in the event of extended power outages—a key principle of passive survivability. (For more on these issues, see “Design for Adaptation: Living in a Climate-Changing World,”
EBN Sept. 2009
and “Passive Survivability: A New Design Criterion for Buildings,”
EBN May 2006
Designers and builders seeking to create green buildings need to focus on the building—what it is and how it’s designed and built to use less energy and water and reduce environmental impacts in other ways. But designers and builders can only go so far; the environmental footprint of a building also depends greatly on how it is operated. Many of the following priorities parallel the outcome priorities described above—but they focus on the building
it is completed. Effective use of occupant surveys and commissioning (see “Retrocommissioning: Big Savings for Big Buildings,”
EBN Oct. 2010
) can play a big role in accomplishing many of these priorities.
The way a building is operated has tremendous impact on its energy use. Two identical buildings can vary in their energy usage by a factor of two or even more, based on differences in operation. Education of building occupants is key to this—turning off lights when leaving a room, setting back thermostat set points for times when less heating or cooling is needed, and lowering blinds to reduce solar heat gain, for example. Companies can also dictate certain energy-saving outcomes, for example by insisting that employees turn off computer monitors when they leave the office at the end of the day, or providing occupancy sensors that do that job.
Employers can reduce the energy used in commuting by providing incentives to avoid commuting in single-occupancy vehicles: eliminating free parking, providing public transit vouchers, offering flex-time to permit bicycle commuting during low-traffic periods, providing a loaner vehicle for employees who don’t drive to work, and offering recognition and rewards for low-energy commuting.
Removal of lawn from around the Las Vegas home in the foreground results in dramatic water savings—while the property beyond has a large irrigated lawn.
Education is key in helping to reduce water use in buildings, especially in homes: operating dishwashers only with full loads; not running the water continuously when scraping dishes, brushing teeth, or shaving; and taking shorter showers. Outdoors, water-efficient landscape management practices can make huge differences in water consumption. For starters, lawn area can be reduced and low-water plantings installed so that irrigation can be greatly reduced or eliminated. When irrigation is needed, better practices can be instituted to irrigate only when needed; automated systems are available to facilitate this.
We can go only so far in keeping the indoor environment healthy through design, product specifications, and construction. We also need to address how the building is operated (turning on exhaust fans while showering and using range hoods, for example); carefully choosing furniture and fittings to support a healthy environment; and choosing green products for cleaning and maintaining the building. Certified green cleaning products are common, perform well, and cost no more.
Durability is partly about the products and materials we install in buildings and the construction details we use to prevent moisture damage and other problems, but it is also about how well we operate and maintain a building. Proper maintenance involves such actions as fixing leaks in the building enclosure that allow moisture to enter the building; promptly fixing plumbing leaks; replacing worn hoses on washing machines and other equipment to prevent leaks; cleaning condensate drains to prevent overflow; painting or staining outside surfaces to prevent UV damage to the substrates; inspecting for termite tunnels and responding to problems that are found; removing vegetation that is too close to the building; and generally keeping an eye out for needed upkeep and repairs.
Porous pavement, as used at the Southface Energy Institute in Atlanta (pictured here), helps to reduce stormwater runoff, which, in turn, helps protect ecosystems in the watershed.
The land around most buildings is highly damaged from an ecological standpoint. Turf grass, for example, is a monoculture of nonnative species that, in many areas, requires life-support infusions of chemical fertilizers, herbicides, and water. It is possible to do much better by restoring the landscapes around our buildings so that they can provide wildlife habitat and diverse plant communities. While this strategy may be most applicable to larger sites in rural areas, it can also apply to urban lots, where even a few square feet of planter bed can provide habitat for butterflies and birds.
There are many ways we can encourage and inspire environmentally responsible practices in the workplace and home. Convenient storage for recyclables, compost bins for organic waste, and easy-to-access bicycle racks in the garage or covered bike storage at the workplace are just a few of many ways that we can make it easy for company employees or homeowners to be good stewards of the environment and healthy living. Signage at the workplace and schools can provide reminders about green operations, like turning out the lights, recycling, and avoiding smoking or idling vehicles near building entrances and openings.
There are risks in creating lists of priorities such as those presented here. The greatest risk is that these will be considered absolutes, rather than general guidance. Every situation is different. In Phoenix, water may well be the number-one priority. In a building along the New Jersey Turnpike or in downtown New York City, reducing air pollution caused by transportation systems might be number one. Priorities will often vary from one project to another. Consider this food for thought, not answers.
Our hope is that these lists of priorities will inspire reflection by readers. What are your top priorities for your next project? Why? Share your thoughts in the comments section below.
Receive continuing education credit for reading this article. The American Institute of Architects (AIA) has approved this course for 1 HSW/SD Learning Unit. The Green Building Certification Institute (GBCI) has approved the technical and instructional quality of this course for 1 GBCI CE hour towards the LEED Credential Maintenance Program.
Upon completing this course, participants will be able to:
- Define green building priorities from a few different angles (separating process priorities from outcome priorities).
- Differentiate those priorities that are determined during design and construction from those that come into play during operation (without forgetting that the two are usually related).
- List some macro-scale priorities for the green building movement (detailing tips to success).
- Describe real-world benefits to choosing wisely both process and outcome priorities.
To earn continuing education credit, make sure you are logged into your personal BuildingGreen account, then read this article and pass this quiz.
November 1, 2010