Sustainable Building Ratings - LEED and Living Buildings

There is a saying that "if you want to pay attention to something, you need to measure it." As you are hopefully aware, there are many ways that buildings and urban/suburban development impact sustainability, e.g. through energy use, natural resource use, waste generation, impact on ecosystems, impact on biodiversity, impacts on pollution, and more. If we want to minimize these impacts and to be more sustainable, we need to figure out a way to measure these impacts. Enter green building ratings systems, aka green building metrics. There are too many ratings sytems to fully cover here, but the following provides some insight into some of the more common ones, as well as some that are less common.

Leadership in Energy and Environmental Design

Take a minute or two to think about the following (feel free to write down your answers): If you wanted to compare how sustainable one building is compared to another building, what would you look for? Think of specific things that 1) impact sustainability and 2) can be measured. 

In the 1990s, the U.S. Green Building Council (USGBC) undertook the same exercise. The result of this was Leadership in Energy and Environmental Design (LEED). LEED was the first widely-accepted "green" building rating system, and is now recognized worldwide. (Side note: the USGBC is a non-profit organization that provides an incredible amount of resources related to sustainable builiding design, many of them freely available. See their Courses and Events site for details. There are also many local chapters that host events.)  

As you can see, LEED is a points-based rating system. Remember all of those aspects of sustainable buildings you listed at the beginning of this page? LEED almost certainly provides "points" for each one of them. On a basic level, a building gets a specific amount of points for sustainable physical features such as water reduction, energy efficiency, renewable energy, use of native plants, use of local materials, use of non-toxic materials, and more subtle ones such as promoting public transportation, providing bike infrastructure, and designing the building to be used as an educational tool. Afte the building is designed and tested, the building achieves a certification level based on the points earned:

• LEED Certified: 40-49 points
• LEED Silver: 50 - 59 points
• LEED Gold: 60 - 79 points
• LEED Platinum: 80+ points

There are more complexities to actually getting certification, e.g. the the builiding owner works with a LEED professional and registers with USGBC from the outset, etc., but that goes beyond the scope of this course. There are also a number of different types of certifications, from single new buildings to interior design to operations and maintenance and more. More information on these is here. If you are interested in reading more about the full LEED process, you can dig into the details here. Note that there are job and training opportunities in this process. For more information see their Credentials site.

One of the common critiques of LEED is that building owners/designers are not required to check all of the boxes (literally, in this case). In other words, it is possible to have a LEED building that overuses water, does not provide 100% of it's own energy, does not use entirely non-toxic or local resources, and so forth. You can pick and choose what you want to address, and the only penalty is that you might not get the certification level that you wanted. In addition, a building receives its LEED rating before the building is used. This can be a problem if the folks using the building do not operate it in such a way that the LEED goals are accomplished. For example, if the building has high levels of insulation and air sealing but the building occupants turn the thermostat up too high or low, or leave windows open, etc., then the building may use much more energy than the design claims.

The Living Building Challenge seeks to address these points, but more importantly it seeks to be the most robust and holistic sustainable building rating system available. 

Living Buildings

The Living Building Challenge is overseen by the Living Future Institute. Their goal is to "move beyond merely being less bad and to become truly regenerative." Based on personal experience and extensive research, Living Building Certification is indeed the most robust and holistically sustainable building rating system available today. 

As you read and saw, the core questions asked by the International Living Future Institute (ILFI) are:

1. What if every single act of design and construction made the world a better place?
2. What does 'good' look like?

It is important to take a minute to think about the implications of the first question in particular. The goal of ILFI goes beyond simply not making things worse in terms of sustainability to actually making things better by building buildings. The intent is summarized when they say: “Nothing less than a sea change in building, infrastructure and community design is required. Indeed, this focus needs to be the great work of our generation. We must remake our cities, towns, neighborhoods, homes and offices, and all the spaces and infrastructure in between. This is part of the necessary process of reinventing our relationship with the natural world and each other—reestablishing ourselves as not separate from, but part of nature, ‘because the living environment is what really sustains us.’” The Living Building Challenge is nothing if not ambitious! 

The Living Building Challenge has seven (7) "petals" for certification. Each petal represents a different category of sustainability:

1. Place: restoring a healthy coexistence with nature
2. Water:  creating water independent sites, buildings and communities
3. Energy:  Relying only on current solar income
4. Health + Happiness: Maximizing physical and psychological health and well being
5. Materials: endorsing products and processes that are safe for all species through time
6. Equity:  supporting a just, equitable world
7. Beauty:  celebrating design that creates transformative change

There are twenty (20) total "imperatives" within these petals. Each imperative has a specific, measurable standard that must be met in order to receive certification.

Figure 5.4. Living Building Certification summary matrix. Click the image for a resizable image.

Credit: International Living Future Institute

Among the standards required are:

• Net positive water: "Project water use and release must work in harmony with the natural water flows of the site and its surroundings. One hundred percent of the project’s water needs must be supplied by captured precipitation or other natural closed-loop water systems, and/or by recycling used project water, and must be purified as needed without the use of chemicals. All stormwater and water discharge, including grey and black water, must  be treated onsite and managed either through reuse, a closed loop system, or infiltration. Excess stormwater can be released onto adjacent sites under certain conditions" (source: ILFI).
• Net positive energy: "One hundred and five percent of the project’s energy needs must be supplied by on-site renewable energy on a net annual basis, without the use of on-site combustion.15 Projects must provide on-site energy storage for resiliency" (source: ILFI)
• Habitat exchange: "For each hectare of development, an equal amount of land away from the project site must be set aside in perpetuity through the Institute’s Living Future Habitat Exchange Program or an approved Land Trust organization. The minimum offset amount is 0.4 hectare." (source: ILSI)
• No red-listed products: The ILSI maintains a list of "red-listed" chemicals that cannot be used in Living Buildings because they are "materials, chemicals, and elements known to pose serious risks to human health and the greater ecosystem that are prevalent in the building products industry" (source: ILFI).

As you can see, there are a few things that separate Living Buildings from LEED (and other) sustainable building metrics. The list is long, but primary among them are the following "Principles that govern the standard":

• "Living Building Challenge compliance is based on actual, rather than modeled or anticipated, performance. Therefore, projects must be operational for at least twelve consecutive months prior to audit to verify Imperative compliance.
•  All Living Building Challenge projects must be holistic—addressing aspects of all seven Petals through the Core Imperatives." (Source: ILFI)

As a result of this being such a robust standard (and the fact that it must be used for a year prior to certification), there are only 30 fully certified Living Buildings in the world, as compared to thousands of LEED buildings.