LEED
[5] In the US, the District of Columbia consistently leads in LEED-certified square footage per capita,[6] followed in 2022 by the top-ranking states of Massachusetts, Illinois, New York, California, and Maryland.
As of 2022[update], based on certified square feet per capita, the leading five states (after the District of Columbia) were Massachusetts, Illinois, New York, California, and Maryland.
[26][27] A key player in developing the Leadership in Energy and Environmental Design (LEED) green certification program was Natural Resources Defense Council (NRDC) senior scientist Robert K.
[29] Over two decades, Watson led a broad-based consensus process, bringing together non-profit organizations, government agencies, architects, engineers, developers, builders, product manufacturers and other industry leaders.
In 2013, the states of Alabama, Georgia and Mississippi effectively banned the use of LEED in new public buildings, in favor of other industry standards that the USGBC considers too lax.
Under LEED 2009, an evaluated project scores points to a possible maximum of 100 across six categories: sustainable sites (SS), water efficiency (WE), energy and atmosphere (EA), materials and resources (MR), indoor environment quality (IEQ) and design innovation (INNO).
Additional performance categories for residences (LEED for Homes) recognize the importance of transportation access, open space, and outdoor physical activity, and the need for buildings and settlements to educate occupants.
[c][64][65] Buildings can qualify for four levels of certification: The aim of LEED 2009 is to allocate points "based on the potential environmental impacts and human benefits of each credit".
The scorecard expresses three global goals of climate action (worth 50% of the certification points), quality of life (25%) and conservation and ecological restoration (25%) in terms of five principles: decarbonization, ecosystems, equity, health and resilience.
[82] Buildings in Canada such as Winnipeg's Canadian Museum for Human Rights are LEED certified due to practices including the use of rainwater harvesting, green roofs, and natural lighting.
Depending on location (climate) and building size, the standard provides requirements for heating, ventilation and air-conditioning (HVAC) system type, and wall and window definitions.
They give the example of debating whether to add a reflective roof, used to can counter "heat island" effects in urban areas, to a building high in the Rocky Mountains.
[111] Both Speck and Owen make the point that a building-centric standard that doesn't consider location will inevitably undervalue the benefits of people living closer together in cities, compared to the costs of automobile-oriented suburban sprawl.
Research papers have tended to address performance and effectiveness of LEED in two credit category areas: energy[115] (EA) and indoor environment quality (IEQ).
[118][115] In 2018, Pushkar examined LEED-NC 2009 (v3) Certified-level certified projects from countries in northern (Finland, Sweden) and southern (Turkey, Spain) regions of Europe to see how different types of credits are understood and applied.
Pushkar found that credit achievements were similar within regions and countries for Indoor Environmental Quality (EQ), Materials and Resources (MR), Sustainable Sites (SS), and Water Efficiency (WE), but differed for Energy and Atmosphere (EA).
Sustainable Sites (SS) and Water Efficiency (WE) were high achievement areas, scoring 80–100% and 70–75%; Indoor Environmental Quality was intermediate (40–60%); and Materials and Resources (MR) was low (20–40%).
[120] In 2009, architectural scientist Guy Newsham (et al.) of the National Research Council of Canada (NRC) re-analyzed a dataset of 100 LEED certified (v3 or earlier version) buildings.
[115] In 2009 physicist John Scofield published an article in response to Newsham et al., analyzing the same database of LEED buildings and arriving at different conclusions.
[65][124] In 2014, architect Gwen Fuertes and engineer Stefano Schiavon[125] developed the first study that analyzes plug loads using LEED-documented data from certified projects.
Comparisons of LEED and non-LEED buildings therefore need to consider age as well as size, use, occupant behavior, and location aspects such as climate zone.
POE research emphasizes the need to collect and analyze actual occupancy data from existing buildings, to better understand how people are using spaces and resources.
"[132] The USGBC includes the following considerations for attaining IEQ credits: indoor air quality, the level of volatile organic compounds (VOC), lighting, thermal comfort, and daylighting and views.
SDA is a metric that measures the annual sufficiency of daylight levels in interior spaces and ASE describes the potential for visual discomfort by direct sunlight and glare.
The threshold recommended by LEED for ASE is that no more than 10% of regularly occupied floor area can be exposed to more than 1000 lux of direct sunlight for more than 250 hours per year.
[140] While LEED v4 introduced “Impact Categories” as system goals, Greer suggests that closer linkages are needed between design points and outcomes, and that issues like supply chains, infrastructure, and regionalized variability should be considered.
Another way LEED has affected research is that designers and architects focus on creating spaces that are modular and flexible to ensure a longer lifespan while simultaneously sourcing products that are resilient through consistent use.
[146] In Milan, a university-corporate partnership sought to produce semi-transparent solar panels to take the place of ordinary windows in glass-facade high-rise buildings.
It provides searchable access to a database of activities, buildings, places and collections of green building-related information from many sources and programs, including LEED projects.
It generates its own energy using solar power and ground-source heat pumps and utilizes extensive KNX technologies to automate the building's environmental controls.
