LEED which stands for Leadership in Energy and Environmental Design is one of the most common sustainable building rating systems used in the United States and around the world. LEED is administered by the U.S. Green Building Council (USGBC), which many people have also heard of. Potential projects are rated by the Green Building Certification Institute (GBCI). There are multiple project typologies that can qualify for LEED certification, including Building Design and Construction (BD+C), Interior Design and Construction (ID+C), Operations and Maintenance (O+M), and ND Neighborhood development. Additionally, LEED certifies smaller residential projects and larger communities. Additional rating systems and pilot rating systems are available to specific project types pursuing LEED certification.
By The Numbers
There are over 100,000 LEED certified projects around the world! A majority of those projects are in the United States. The USGBC’s website lists each one with project images and even detailed project data. It is fun to look for LEED certified projects in your home state or region. I discovered several projects in my state that had achieved certification recently. Reading about these real life case studies is one of the best ways for anyone to learn more about sustainable design. We’ll explore a case study built in my hometown later in this post.
LEED certification is earned on four different levels. The highest level of certification, Platinum, represents LEED projects that have achieved at least 80 points on the LEED scorecard. Next, Gold represents projects with 60-79 points. Silver projects earn between 50 and 59 points. Lastly, projects that are LEED Certified earned between 40 and 49 points. LEED projects have a scorecard that shows which LEED rating categories the project achieved.
Projects seeking LEED certification must achieve pre-determined prerequisites based on the project type and then attempt to earn credits to earn a total score. The scorecard for most LEED projects will cover the categories listed below or a similar list that is specific to a certain project type.
Location and Transportation
Project teams consider the vehicle parking requirements as well as other forms of transportation in an attempt to encourage building occupants to reduce vehicle miles traveled. Providing access and incentives to travel by bicycle, bus, carpool, electric car, etc. can earn a project more points in this category. If possible, the project location should be located near parks, sidewalks, bus stops, grocery stores, and other sites that can improve walkability and overall human health.
A project’s site is such a crucial part of its overall sustainability. The project team must consider the impacts that construction will have on a site’s ecological systems and surrounding land. A new building can add light pollution, block natural views, and divert stormwater in addition to contributing to the area’s heat island effect. The project site design must address these areas and create ways that the construction itself can be less wasteful and less harmful on existing natural features.
Water efficiency is key to designing a sustainable project that meets LEED criteria. Project teams should find ways to reduce the water demand for the site as well as the building systems. Water metering is a strategy used to monitor a building’s indoor and outdoor water use.
Energy and Atmosphere
LEED buildings are generally high performing in terms of energy demand and use. LEED requires a minimum energy performance that is compared to a baseline and is verified with performance testing. Commissioning of the building’s energy systems before, during, and after occupancy allows building owners to monitor and optimize their long term energy use. This is also the category that considers renewable energy use including solar and wind energy.
Materials and Resources
Buildings require tons of materials, and those materials require manufacturing and transportation processes. This LEED scorecard category gives points for responsible material selection including those that are non-toxic and contain recycled content. This category emphasizes managing waste during construction as well as eliminating or reducing materials containing mercury and lead.
Indoor Environmental Quality
Providing a healthy indoor environment is one of the most important goals of a project design team. So, project teams need to design building systems that contribute to that goal. A major part of indoor air quality is eliminating tobacco smoke and reducing the effects of off-gassing from building materials. Indoor air quality is just as important during construction as it is after occupancy. The interior lighting, both artificial and natural should enhance an occupant’s experience in the building, not detract from it. Additionally, occupants should have access to outdoor views. The interior temperature and acoustic levels should be controlled and at healthy levels.
Project teams pursuing LEED certification can receive credits for sustainability strategies not already outlined in the LEED scorecard. These innovative strategies have to meet certain requirements and/or greatly exceed a current standard. Project teams utilizing a LEED Accredited Professional or LEED AP can also earn points in this category.
Project teams that utilize locally available resources to build their projects can earn points in this category. For example, acquiring locally made materials can reduce the amount of transportation required to get the materials on site.
Evolving for a Better Future
As with all modern organizations, the need to constantly improve is met with innovation and new versions of standard operating systems. LEED keeps up with new research, data, and input from professionals by releasing new versions of its rating system. In 2019, the new version of LEED (4.1) was rolled out. It keeps the structure of the rating system while addressing the latest advancements and issues in equity, climate, and health. This new version emphasizes the integrative design process, which promotes shared goals and higher quality design and construction. A letter describing the project’s integrative design process is required to be written and signed by all project stakeholders. Additionally, LEED 4.1 has requirements for bolstering buildings against the threat of natural and unnatural disasters. We know that natural disasters, pandemics, and other concerns can greatly alter our safe access to buildings. Using integrative design, project teams can anticipate and address disasters and create designs that reduce the impact of disasters on human and environmental health.
Sustainable and non toxic materials are a major part of indoor air quality and building occupant health. LEED 4.1 places emphasis on the distribution and transportation of building materials to reduce the impact that material acquisition has on the environment. The entire life cycle of building materials can be analyzed and utilized to help project teams decide to reuse materials, purchase from responsible manufacturers, and reduce waste.
As a real world LEEDership example, I thought we could explore a LEED project from my hometown. The Rogers County Sheriff’s Office in Claremore, Oklahoma was LEED BD+C certified in 2019. The architect on the project was SGA Design Group, based in Tulsa, Oklahoma. SGA has an impressive sustainable project portfolio. Kim Limbaugh, the Director of Sustainability for SGA discussed the project for a USGBC article, which is where I first read about the project. Limbaugh emphasized how the project is a great example of sustainable renovation projects. There may be a misconception that only new buildings can achieve LEED certification or other sustainability measures. Renovation projects can achieve many sustainable building credentials. They are already reducing the amount of raw materials necessary, since the building foundation and structure are usually in place.
The sheriff’s office is in a historic building built in 1935 and was originally Claremore’s post office. The renovation cost $1.6 million and covered 8,000 square feet. The historical building had many historical characteristics typical of the early 1900s, so the design team kept as much of that character as possible. Historical architectural features include skylights and archways as well as tile that is reminiscent of the building’s origin.
It is located in the middle of town in Claremore, and I have driven by it a thousand times. The site is near several city buildings as well as restaurants, drugstores, banks and gas stations. Proximity to these and other important locales earned the project points in LEED’s Sustainable Sites category.
Thankfully, I haven’t spent much time inside the building. Those that do spend time in the sheriff’s office can benefit from high efficiency building systems. The building’s energy costs are 42% less than a standard similar building. How impressive. Additionally, the lighting system is motion-activated and utilizes LED fixtures to reduce the building’s energy consumption even more. The HVAC (heating, ventilation, and air conditioning) is a variable refrigerant volume (VRV). This type of system heats and cools spaces independent of each other. It is also smart enough to use heat from one space and redirect it to another space that needs it.
I am thankful that the men and women working in the Sheriff’s Office enjoy clean air, natural light, and lower energy usage. This project is a wonderful example of a LEED certified renovation project that is publicly funded.
LEED projects recertify at certain predefined intervals after the initial certification. This process encourages projects to maintain their healthy, high performing buildings and systems. So, let’s hope that we see more and more LEED certified buildings around the world. LEED will continue to “LEED” the way toward a more sustainable future for our built environments and the humans that use them.
plus.usgbc.org First Responder Buildings Become Leaders in Sustainable Design Across the United States By Lorne Bell