Leadership in Energy and Environmental Design (LEED) is a green building certification program used worldwide.^[3] Developed by the non-profit U.S. Green Building Council (USGBC), it includes a set of rating systems for the design, construction, operation, and maintenance of green buildings, homes, and neighborhoods, which aims to help building owners and operators be environmentally responsible and use resources efficiently.

As of 2023^[update] there were over 105,000 LEED-certified buildings and over 205,000 LEED-accredited professionals in 185 countries worldwide.^[4] In the USA, the District of Columbia consistently leads in LEED-certified square footage per capita,^[5] followed in 2022 by the top-ranking states of Massachusetts, Illinois, New York, California, and Maryland.^[4] Outside the United States, the top-ranking countries for 2022 were Mainland China, India, Canada, Brazil, and Sweden.^[6] LEED Canada has developed a separate rating system adapted to the Canadian climate and regulations.

Some U.S. federal agencies, state and local governments require or reward LEED certification. This can include tax credits, zoning allowances, reduced fees, and expedited permitting. Offices, healthcare-, and education-related buildings are the most frequent LEED-certified buildings in the US (over 60%), followed by warehouses, distribution centers, retail projects and multifamily dwellings (another 20%).^[7] Studies have found that for-rent LEED office spaces generally have higher rents and occupancy rates and lower capitalization rates.

LEED is a design tool rather than a performance-measurement tool and has focused on energy modeling rather than actual energy consumption.^[8] It has been criticized for a point system that can lead to inappropriate design choices and the prioritization of LEED certification points over actual energy conservation;^[9][10] for lacking climate specificity;^[10] for not sufficiently addressing issues of climate change and extreme weather;^[11] and for not incorporating principles of a circular economy.^[12] LEED v5 is projected to be published as of 1 January 2024^[13] and may address some of the previous criticisms.^[14][15]

Despite concerns, LEED has been described as a "transformative force in the design and construction industry".^[9] LEED is credited with providing a framework for green building, expanding the use of green practices and products in buildings, encouraging sustainable forestry, and helping professionals to consider buildings in terms of the well-being of their occupants and as part of larger systems.^[9]

History

In April 1993, the U.S. Green Building Council (USGBC) was founded by Rick Fedrizzi, the head of environmental marketing at Carrier, real estate developer David Gottfried, and environmental lawyer Michael Italiano. Representatives from 60 firms and nonprofits met at the American Institute of Architects to discuss organizing within the building industry to support green building and develop a green building rating system.^[21][22][23] Also influential early on was architect Bob Berkebile.^[24]

Fedrizzi served as the volunteer founding chair of USGBC from 1993 to 2004, and became its CEO as of 2004. As of November 4, 2016, he was succeeded as president and CEO of USGBC by Mahesh Ramanujam.^[22][25] Ramanujam served as CEO until 2021. Peter Templeton became interim president and CEO of USGBC as of November 1, 2021.^[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. Watson.^[28][29] It was Watson, sometimes referred to as the "Founding Father of LEED",^[28] who came up with the acronym.^[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. The original planning group consisted of Watson, Mike Italiano, architect Bill Reed (founding LEED Technical Committee co-chair 1994–2003),^[30][31][32] architect Sandy Mendler,^[30][33][34] builder Gerard Heiber^[30][33][35] and engineer Richard Bourne.^[30]

Tom Paladino and Lynne Barker (formerly King) co-chaired the LEED Pilot Committee^[31] from 1996–2001.^[36] Scot Horst chaired the LEED Steering Committee^[37] beginning in 2005 and was deeply involved in the development of LEED 2009.^[38] Joel Ann Todd took over as chair of the steering committee from 2009 to 2013, working to develop LEED v4,^[39] and introducing social equity credits.^[40] Other steering committee chairs include Chris Schaffner (2019)^[41] and Jennifer Sanguinetti (2020).^[42] Chairs of the USGBC's Energy and Atmosphere Technical Advisory Group for LEED technology have included Gregory Kats.^[43]

The LEED initiative has been strongly supported by the USGBC Board of Directors, including Chair of the Board of Directors Steven Winter (1999–2003).^[44] The current chair of the Board of Directors is Anyeley Hallová (2023).^[45]

LEED has grown from one standard for new construction to a comprehensive system of interrelated standards covering aspects from the design and construction to the maintenance and operation of buildings. LEED has also grown from six committee volunteers to an organization of 122,626 volunteers, professionals and staff.^[46]

As of 2023^[update] more than 185,000 LEED projects representing over 28 billion square feet (2.6×10^⁹ m²) have been proposed worldwide, and more than 105,000 projects representing over 12 billion square feet (1.1×10^⁹ m²) have been certified in 185 countries.^[4]

Many U.S. federal agencies, states, and local governments require or reward LEED certification. As of 2022^[update] the leading five states, based on certified square feet per capita were Massachusetts, Illinois, New York, California, and Maryland.^[4]

However, lumber, chemical and plastics trade groups have lobbied to weaken the application of LEED guidelines in several southern states. 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.^[47][48][49] LEED is considered a target of a type of disinformation attack known as astroturfing, involving "fake grassroots organizations usually sponsored by large corporations".^[50]

Unlike model building codes, such as the International Building Code, only members of the USGBC and specific "in-house" committees may add to, subtract from, or edit the standard, subject to an internal review process. Proposals to modify the LEED standards are offered and publicly reviewed by USGBC's member organizations, of which there were 4551 as of October 2023.^[51]

USGBC's Green Business Certification Inc. (GBCI) offers various accreditations to people who demonstrate knowledge of the LEED rating system, including LEED Accredited Professional (LEED AP), LEED Green Associate, and LEED Fellow.^[52] GBCI also certifies projects pursuing LEED.

Rating systems

LEED has evolved since 1998 to more accurately represent and incorporate emerging green building technologies. The pilot version, LEED New Construction (NC) v1.0, led to LEED NCv2.0, LEED NCv2.2 in 2005, LEED 2009 (a.k.a. LEED v3) in 2009, and LEED v4 in November 2013. LEED 2009 was depreciated for new projects registered from October 31, 2016.^[53] LEED v4.1 was released on April 2, 2019.^[54] LEED v5 is expected to be released as of 1 January 2024.^[13]

LEED also forms the basis for other sustainability rating systems such as the U.S. Environmental Protection Agency's (EPA) Labs21 and LEED Canada. The Australian Green Star is based on both LEED and the UK's Building Research Establishment Environmental Assessment Methodology (BREEAM).^[55]

LEED v3 (2009)

LEED 2009 encompasses ten rating systems for the design, construction and operation of buildings, homes and neighborhoods. Five overarching categories correspond to the specialties available under the LEED professional program. That suite consists of:^[56]

• Green building design and construction (BD+C) – for new construction, core and shell,^[a] schools, retail spaces (new constructions and major renovations), and healthcare facilities
• Green interior design and construction – for commercial and retail interiors
• Green building operations and maintenance
• Green neighborhood development
• Green home design and construction^[b]

LEED v3 aligned credits across all LEED rating systems, weighted by environmental priority.^[58] It reflects a continuous development process, with a revised third-party certification program and online resources.

Under LEED 2009, an evaluated project scores points to a possible maximum of 100 across six categories: sustainable sites, water efficiency, energy and atmosphere, materials and resources, indoor environment quality (IEQ) and design innovation. Each of these categories also includes mandatory requirements, which receive no points. Up to 10 additional points may be earned: 4 for regional priority credits and 6 for innovation in design. Additional performance categories for residences (LEED for Homes) recognize the importance of transportation access, open space, and outdoor physical activity outdoors, and the need for buildings and settlements to educate occupants.^[c][59]

Buildings can qualify for four levels of certification:

• Certified: 40–49 points
• Silver: 50–59 points
• Gold: 60–79 points
• Platinum: 80 points and above

The aim of LEED 2009 is to allocate points "based on the potential environmental impacts and human benefits of each credit". These are weighed using the environmental impact categories of the EPA's Tools for the Reduction and Assessment of Chemical and Other Environmental Impacts (TRACI)^[61] and the environmental-impact weighting scheme developed by the National Institute of Standards and Technology (NIST).

Prior to LEED 2009 evaluation and certification, a building must comply with environmental laws and regulations, occupancy scenarios, building permanence and pre-rating completion, site boundaries and area-to-site ratios. Its owner must share data on the building's energy and water use for five years after occupancy (for new construction) or date of certification (for existing buildings).^[62]

The credit weighting process has the following steps: First, a collection of reference buildings are assessed to estimate the environmental impacts of similar buildings. NIST weightings are then applied to judge the relative importance of these impacts in each category. Data regarding actual impacts on environmental and human health are then used to assign points to individual categories and measures. This system results in a weighted average for each rating scheme based upon actual impacts and the relative importance of those impacts to human health and environmental quality.^[63]

The LEED council also appears to have assigned credit and measured weighting based upon the market implications of point allocation.^[63]

From 2010, buildings can use carbon offsets to achieve green power credits for LEED-NC (new construction certification).^[64]

LEED v4 (2014)

For LEED BD+C v4 credit, the IEQ category addresses thermal, visual, and acoustic comfort as well as indoor air quality.^[65] Laboratory and field research have directly linked occupants' satisfaction and performance to the building's thermal conditions.^[66] Energy reduction goals can be supported while improving thermal satisfaction. For example, providing occupants control over the thermostat or operable windows allows for comfort across a wider range of temperatures.^[67][68]

LEED v4.1 (2019)

On April 2, 2019, the USGBC released LEED v4.1, a new version of the LEED green building program, designed for use with cities, communities and homes.^[54][28]

LEED v5 (Draft, 2023)

As of January 2023, USGBC began to develop LEED v5. LEED v5 is the first version of the LEED rating system to be based on the June 2022 Future of LEED principles.^[13] The LEED v5 rating system will cover both new construction and existing buildings. A draft version was discussed at Greenbuild 2023.^[69][70][71] A final version is expected to be published as of 1 January 2024.^[13]

LEED v5 is expected to have three system goals, resulting in significant changes to its scoring breakdown. It will emphasize:

1. Climate action (50% of possible points)
2. Quality of life (25%)
3. Ecological conservation and restoration (25%)^[72]

It is expected to address issues of resiliency, equity, and health and well-being as well as decarbonization, and biodiversity.^[72][69]

LEED Canada

In 2003, the Canada Green Building Council (CAGBC) received permission to create LEED Canada-NC v1.0, which was based upon LEED-NC 2.0.^[73] As of 2021, Canada ranked second in the world (not including the USA) in its number of LEED-certified projects and square feet of space.^[74] 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.^[75]

As of March 18, 2022, the Canada Green Building Council took over direct oversight for LEED™ green building certification of projects in Canada, formerly done by GBCI Canada. CAGBC will continue to work with Green Business Certification Inc. (GBCI) and USGBC while consolidating certification and credentialing for CAGBC's Zero Carbon Building Standards, LEED, TRUE,^[76] and Investor Ready Energy Efficiency (IREE).^[77]

Certification process

LEED certification is granted by the Green Building Certification Institute (GBCI), which arranges third-party verification of a project's compliance with the LEED requirements. The certification process for design teams consists of the design application, under the purview of the architect and the engineer and documented in the official construction drawings, and the construction application, under the purview of the building contractor and documented during the construction and commissioning of the building.

A fee is required to register the building, and to submit the design and construction applications. Total fees are assessed based on building area, ranging from a minimum of $2,900 to over $1 million for a large project.^[78] "Soft" costs – i.e., added costs to the building project to qualify for LEED certification – may range from 1% to 6% of the total project cost. The average cost increase was about 2%, or an extra $3–$5 per square foot.^[79]

The application review and certification process is conducted through LEED Online, USGBC's web-based service. The GBCI also utilizes LEED Online to conduct their reviews.

LEED energy modeling

Applicants have the option of achieving credit points by building energy models.^[d] One model represents the building as designed, and a second model represents a baseline building in the same location, with the same geometry and occupancy. 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. This allows for a comparison with emphasis on factors that heavily influence energy consumption. The number of points achieved in this credit is proportional to the predicted energy savings.

This method has been criticized for inaccurately predicting actual energy usage. The USGBC admits that "current information indicates that most buildings do not perform as well as design metrics indicate. As a result, building owners might not obtain the benefits promised."^[80]

LEED for Homes rating system

The process of the LEED for Homes rating system, available in the U.S.,^[81] Canada and Sweden,^[82] differs significantly from the LEED NC rating system. LEED for Homes projects are low-rise residential and are required to work with either an American^[83] or a Canadian provider organization^[84] and a green rater. The provider organization helps the project through the process while overseeing the green raters, individuals who conduct two mandatory site inspections: the thermal bypass inspection and the final inspection. Although LEED for Homes is typically viewed by the construction industry as a simpler rating system than LEED NC, the latter does not require an on-site inspection. The provider and rater assist in the certification process but do not themselves certify the project.

Performance

LEED is a design tool and as such has focused on energy modeling, rather than being a performance-measurement tool that measures actual energy consumption.^[8][9][10] LEED uses modeling software to predict future energy use based on intended use. Buildings certified under LEED do not have to prove energy or water efficiency in practice to receive LEED certification points. This has led to criticism of LEED's ability to accurately determine the efficiency of buildings,^[9] and to calls to improve the accuracy of its predictive models.

Research papers provide most of what is known about the performance and effectiveness of LEED. Much of the available research predates 2014, and therefore applies to buildings that were designed under early versions of the LEED rating and certification systems, LEED v3 (2009) or earlier. As pointed out by Newsham et al., many early analyses should be considered as preliminary. Studies should be repeated with longer data history and larger building samples, include newer LEED certified buildings, and clearly identify green-building rating schemes of individual buildings.^[85] Research papers have tended to address performance and effectiveness of LEED in two credit category areas: energy and indoor environment quality (IEQ).

Energy performance research

In 2009, architectural scientist Guy Newsham (et al.) of the National Research Council of Canada (NRC) analyzed a database of 100 LEED certified (v3 or earlier version) buildings.^[85] In this study, each building was paired with a conventional "twin" building within the Commercial Building Energy Consumption Survey (CBECS) database according to building type and occupancy.^[85] On average, LEED buildings consumed 18 to 39% less energy by floor area than the conventional buildings, although 28 to 35% of LEED-certified buildings used more energy.^[85] The paper found no correlation between the number of energy points achieved or LEED certification level and measured building performance.^[85]

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.^[86] Scofield criticized the earlier analysis for focusing on energy per floor area instead of a total energy consumption. Scofield considered source energy^[87] (accounting for energy losses during generation and transmission) as well as site energy, and used area-weighted energy use intensities (EUIs) (energy per unit area per year), when comparing buildings to account for the fact that larger buildings tend to have larger EUIs.^[86] Scofield concluded that, collectively, the LEED-certified buildings showed no significant source energy consumption savings or greenhouse gas emission reductions when compared to non-LEED buildings, although they did consume 10–17% less site energy.^[86]

In 2013 Scofield analyzed 953 New York City office buildings office buildings, of which 21 were LEED-certified, based on publicly available data.^[88] Results were mixed. Although LEED-Gold buildings used 20% less source energy, buildings at the Silver and Certified levels used 11 to 15% more source energy, on average, than conventional buildings.^[88] In 2014, architect Gwen Fuertes and engineer Stefano Schiavon^[89] developed the first study that analyzes plug loads using LEED-documented data from certified projects. The study compared plug load assumptions made by 92 energy modeling practitioners against ASHRAE and Title 24 requirements, and the evaluation of the plug load calculation methodology used by 660 LEED-CI^[90] and 429 LEED-NC^[91] certified projects. They found that energy modelers only considered the energy consumption of predictable plug loads, such as refrigerators, computers and monitors. Overall the results suggested a disconnection between assumptions in the models and the actual performance of buildings.

Energy modeling might be a source of error during the LEED design phase. Engineers Christopher Stoppel and Fernanda Leite evaluated the predicted and actual energy consumption of two twin buildings using the energy model during the LEED design phase and the utility meter data after one year of occupancy. The study's results suggest that mechanical systems turnover and occupancy assumptions significantly differ from predicted to actual values.^[92]

IEQ performance research

The Centers for Disease Control and Prevention (CDC) defines indoor environmental quality (IEQ) as "the quality of a building's environment in relation to the health and wellbeing of those who occupy space within it."^[93] 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. In consideration of a building's indoor environmental quality, published studies have also included factors such as: acoustics, building cleanliness and maintenance, colors and textures, workstation size, ceiling height, window access and shading, surface finishes, furniture adaptability and comfort.^[94][95]

IEQ-related studies provide contrasting results: the first used occupant survey results in 65 LEED buildings and 79 non-LEED buildings and concluded that occupants of both groups had equal satisfaction with the building overall and with the workspace.^[94] The second IEQ study used occupant interviews and physical site measurements at 12 LEED buildings to report superior indoor environment performance compared with 12 similar non-certified buildings.^[95]

In 2013, a paper published by Schiavon and architectural physicist Sergio Altamonte studied occupant IEQ satisfaction in LEED and non-LEED buildings.^[94] Using occupant surveys from the Center for the Built Environment^[96] at Berkeley database,^[97] 65 LEED-certified and 79 non-LEED buildings were analyzed for 15 IEQ-related factors. These factors include the ease of interaction, building cleanliness, the comfort of furnishing, the amount of light, building maintenance, colors and textures, workplace cleanliness, the amount of space, furniture adjustability, visual comfort, air quality, visual privacy, noise, temperature, and sound privacy. The results showed occupants tend to be slightly more satisfied in LEED buildings for the air quality and slightly more dissatisfied with the amount of light. The overall finding was that there was no significant influence of LEED certification on occupant satisfaction in consideration of the overall building and workspace ratings.^[94] The paper noted that the data may not be representative of the entire building stock and a randomized approach was not used in the data assessment.

Based on similar dataset (21,477 occupants) in 2013, Schiavon and Altomonte^[98] found that occupants have equivalent satisfaction levels in LEED and non-LEED buildings when evaluated independently from the following factors: office type, spatial layout, distance from windows, building size, gender, age, type of work, time at workspace, and weekly working hours. LEED certified buildings may provide higher satisfaction in open spaces than in enclosed offices, in smaller buildings than in larger buildings, and to occupants having spent less than one year in their workspaces rather than to those who have used their workspace longer. The study also notes that the positive value of LEED certification from the aspect of occupant satisfaction may tend to decrease with time.

In 2015, a study on indoor environmental quality and the potential health benefits of green-certified buildings was developed by environmental health scientist Joseph Allen (et al.)^[99] showing that green buildings provide better indoor environmental quality with direct benefits to human health of occupants of those buildings in comparison to non-green buildings. One of the limitations of the study was the use of subjective health performance indicators since there is a lack of definition on such indicators by current studies.

Newsham et al. published a detailed study on IEQ and LEED buildings in August 2013.^[95] Field studies and post-occupancy evaluations (POE) were performed in 12 green and 12 conventional buildings across Canada and the northern United States. On-site, 974 workstations were measured for thermal conditions, air quality, acoustics, lighting, workstation size, ceiling height, window access and shading, and surface finishes. Responses were positive in the areas of environmental satisfaction, satisfaction with thermal conditions, satisfaction with outside views, aesthetic appearance, reduced disturbance from HVAC noise, workplace image, night-time sleep quality, mood, physical symptoms, and reduced number of airborne particulates. The results showed green buildings exhibited superior performance compared with similar conventional buildings.^[95]

A 2017 study by Altomonte, Schiavon, et al. investigated whether a green rating itself leads to higher occupant satisfaction with IEQ.^[100] Based on the analysis of a subset of the CBE Occupant IEQ including 11,243 responses from 93 LEED-certified office buildings, this study found that the achievement of a specific IEQ credit did not substantially increase the satisfaction with the corresponding IEQ factor. In addition, the rating level and version of the certification had no impact on workplace satisfaction. There are some possible explanations. Many intervening factors in the time between design and occupancy can alter the existence or performance of the strategies that LEED awarded. IEQ certification metrics also face the challenges from substantial differences that characterize the modern workplace in terms of spatial needs, task requirements, users' characteristics, and disciplines of product design and marketing. Survey participants may also misinterpret the satisfaction with an IEQ parameter, or bias with personal attitudes.^[100]

The daylight credit was updated in LEED v4 to include a simulation option for daylight analysis that uses spatial daylight autonomy (SDA) and annual sunlight exposure (ASE) metrics to evaluate daylight quality in LEED projects. 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. These metrics are approved by the Illuminating Engineering Society of North America (IES) and codified in the LM-83-12 standard.^[101] LEED recommends a minimum of 300 lux for at least 50% of total occupied hours of the year for at least 55% of the occupied floor area. 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. Additionally, LEED requires window shades to be closed when more than 2% of a space is subject to direct sunlight above 1000 lux. According to building scientist Christopher Reinhart, the direct sunlight requirement is a very stringent approach that can discourage good daylight design. Reinhart proposed the application of the direct sunlight criterion only in spaces that require stringent control of sunlight (e.g. desks, white boards, etc.).^[102]

Innovation in design research

The rise in LEED certification also brought forth a new era of construction and building research and ideation. Architects and designers have begun stressing the importance of occupancy health over high efficiency within new construction and have been trying to engage in more conversations with health professionals. Along with this, they also create buildings to perform better and analyze performance data to upkeep the process. 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.^[103]

Innovation in LEED architecture is linked with new designs and high-quality construction. One example is use of nanoparticle technology for consolidation and conservation effects in cultural heritage buildings.^[104] This practice began with the use of calcium hydroxide nano-particles in porous structures to improve mechanical strength. Titanium, silica, and aluminum-based compounds may also be used.^[105]

Material technology and construction techniques could be among first issues to consider in building design. For the facade of high-rise buildings, such as the Empire State Building, the surface area provides opportunities for design innovation.^[106] VOC released from construction materials into the air is another challenge to address.^[107]

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.^[108] Similar concepts are under development elsewhere, with considerable market potential.^[109][110]

The Manzara Adalar skyscraper project in Istanbul, designed by Zaha Hadid, saw considerable innovation through the use of communal rooms, outdoor spaces, and natural lighting^[111] as part of the Urban Transformation Project of the Kartal port region.^{[112][113][114]}

Extreme structures that have received LEED certification include: Amorepacific Headquarters in Seoul by David Chipperfield Architects;^[115] Project: Brave New World: SFMOMA by Snøhetta in San Francisco, California;^[116] Project: UFO in a Sequinned Dress: Centro Botín in Santander by Renzo Piano; Building Workshop in Zusammenarbeit with Luis Vidal + Architects, in Santander, Spain;^[117] and Project: Vertical factory: Office building in London by Allford Hall Monaghan Morris in London.^[118]

Other related research notes

A 2003 analysis of the savings from green building found in a review of 60 LEED buildings that these buildings were, on average, 25–30% more energy efficient. It also attributed substantial benefits to the increased productivity from the better ventilation, temperature control, lighting control, and reduced indoor air pollution.^[119]

From a financial perspective, several 2008 studies found that LEED for-rent office spaces generally charged higher rent and had higher occupancy rates. Analysis of CoStar Group property data estimated the extra cost for the minimum benefit at 3%, with an additional 2.5% for silver-certified buildings.^[120] More recent studies have confirmed these earlier findings in that certified buildings achieve significantly higher rents, sale prices and occupancy rates as well as lower capitalization rates, potentially reflecting lower investment risk.^{[121][122][123]}

LEED focuses on the design of the building and not on its actual energy consumption, and therefore it has been suggested that LEED buildings should be tracked to discover whether the potential energy savings from the design are being used in practice.^[124]

Directories of LEED-certified projects

The USGBC and Canada Green Building Council maintain online directories of U.S. LEED-certified and LEED Canada-certified projects.^[46][125] In 2012 the USGBC launched the Green Building Information Gateway (GBIG) to connect green building efforts and projects worldwide. 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.^[126]

Professional accreditation

The Green Building Certification Institute (GBCI) describes its LEED professional accreditation as "demonstrat[ing] current knowledge of green building technologies, best practices" and the LEED rating system, to assure the holder's competency as one of "the most qualified, educated, and influential green building professionals in the marketplace."^[127] Credentials include the LEED Green Associate and the various types of specialized LEED Accredited Professionals (AP).

Benefits and disadvantages

LEED-certified buildings are intended to use resources more efficiently when compared to conventional structures inspected only to mandatory building codes. However, analysis of energy and water use data from New York City shows that LEED certification does not necessarily make a building more energy or water efficient.^[9]

Often, when a LEED rating is pursued, the cost of initial design and construction rises. There may be a lack of abundant availability of manufactured building components that meet LEED specifications. There are also added costs in USGBC correspondence, LEED design-aide consultants, and the hiring of the required Commissioning Authority, which are not in themselves necessary for an environmentally responsible project unless seeking LEED certification.^[128]

Proponents argue that these higher initial costs can be mitigated by the savings incurred over time due to projected lower-than-industry-standard operational costs typical of a LEED certified building. This life cycle costing is a method for assessing the total cost of ownership, taking into account all costs of acquiring, owning and operating, and the eventual disposal of a building. Additional economic payback may come in the form of employee productivity gains incurred as a result of working in a healthier environment. Studies suggest that an initial up-front investment of 2% extra yields over ten times that initial investment over the life cycle of the building.^[129]

The USGBC has stated support for Architecture 2030, an effort that has set a goal for a building to operate with no greenhouse-gas-emitting energy by 2030.^[130] In progression toward this,^[131] from LEED's existing certifications,^[132] the Living Building Challenge (LBC) is currently the most stringent sustainable design protocol. It sets 20 imperatives^[133] that compel building owners, designers, operators and tenants beyond current LEED rating levels.^[134]

LEED is a design tool and not a performance measurement tool. It is also not yet climate-specific, although the newest version hopes to partially address this. Because of this, designers may be encouraged to make design choices to gain a LEED point, even though this choice is not optimal for the specific project. Additionally, LEED is not energy-specific; it only measures overall performance, allowing builders to choose how to achieve points under various categories. A USA Today review showed that 7,100 certified commercial building projects targeted cheap and easy green points, such as creating healthy spaces and providing educational displays in the building.^[9] Few builders adopted renewable energy because of the initial cost. Builders game the rating system and use certain performances to compensate for the others, and energy conservation becomes the weakest part in the overall evaluation.

LEED has been developed and continuously modified by workers in the green building industry, especially in the ten largest metro areas in the U.S.; however, LEED certified buildings have been slower to penetrate small and middle markets.^[135][136] There has been criticism that the LEED rating system is not sensitive and does not vary enough with regard to local environmental conditions. For instance, a building in Maine would receive the same credit as a building in Arizona for water conservation, though the principle is more important in the latter case. Another complaint is that certification costs could be better used to make the project more sustainable. Many critics have noted that compliance and certification costs have grown faster than staff support from the USGBC.^[137]

For existing buildings, LEED has developed LEED-EB. Research has demonstrated that buildings that can achieve LEED-EB equivalencies can generate a tremendous return-on-investment.^{[citation needed]} In a 2008 white paper by the Leonardo Academy comparing LEED-EB buildings vs. data from BOMA's Experience Exchange Report 2007 demonstrated LEED-EB certified buildings achieved superior operating-cost savings in 63% of the buildings surveyed ranging from $4.94 to $15.59 per square foot of floor space.^[138] The overall cost of LEED-EB implementation and certification ranged from $0.00 to $6.46 per square foot of floor space, demonstrating that implementation is not expensive, especially in comparison to cost savings.

Incentive programs

Many federal, state, and local governments and school districts have adopted various types of LEED initiatives and incentives.^[139] Many local governments have adopted LEED incentive programs, which can include tax credits, tax breaks, density zoning bonuses, reduced fees, priority or expedited permitting, free or reduced-cost technical assistance, grants and low-interest loans.^[140]

Cincinnati, Ohio, adopted a measure providing an automatic 100% real property tax exemption of the assessed property value for newly constructed or rehabilitated commercial or residential properties that earn a minimum of LEED Certified.^[141] In Nevada, construction materials for a qualifying LEED building are exempt from local taxes. Pieces of construction that are deemed 'inseparable parts', such as concrete or drywall, qualify.^[142] Maryland's High Performance Buildings Act (2008) requires all new public construction and renovations greater than 7,500 sq ft (700 m²) to meet LEED Silver standard or two Green Globes. Between 2009 and 2014, the state is required to fund half of the required additional cost for public school construction or renovation to attain that standard.^[143]

In June 2013, USGBC announced a promotion called LEED Earth that refunds LEED certification fees to the first LEED-certified project in a country that doesn't have one.^[144][145]

For existing buildings, LEED has developed LEED-EB. Research has demonstrated that buildings that can achieve LEED-EB equivalencies can generate a tremendous return-on-investment.^[146]

Delaware currently has a Green Home Rebate incentive program that provides $1,000 – $4,500 rebates to certain new homes that achieve LEED certification.^[147]

Hawaii also features a Priority Permit Processing for Green Buildings which requires each county agency that issues building, construction, or development-related permits to create a policy to provide free priority processing of permit applications for construction projects that integrate energy and environmental design building standards. Such buildings can qualify after being rated at LEED silver or similar a certification.^[148]

Notable certifications

The Philip Merrill Environmental Center was the first building to receive a LEED-Platinum rating, version 1.0. It was recognized as one of the "greenest" buildings constructed in the U.S. in 2001 at the time it was built. Sustainability issues ranging from energy use to material selection were given serious consideration throughout design and construction of this facility.^[149]

The first LEED platinum-rated building outside the U.S. is the CII Sohrabji Godrej Green Business Centre (CII GBC) in Hyderabad, India,^[150] certified in 2003 under LEED version 2.0.^{[151][152][153][154][155]}

Pittsburgh's 1,500,000-square-foot (140,000 m²) David L. Lawrence Convention Center was the first Gold LEED-certified convention center and largest "green" building in the world when it opened in 2003.^[156] It earned Platinum certification in 2012, becoming the only convention center with certifications for both the original building and new construction.^[157]

In Pittsburgh, the visitor's center of Phipps Conservatory & Botanical Gardens received a Silver certification,^[158] its Center for Sustainable Landscapes received a Platinum certification and fulfilled the Living Building Challenge for net-zero energy,^[18] and its greenhouse facility received Platinum certification.^[17]

Also in Pittsburgh, Sota Construction Services' corporate headquarters,^[159] which features a super-efficient thermal envelope using cob walls, a geothermal well, radiant heat flooring, a roof-mounted solar panel array, and daylighting features. It earned a LEED Platinum rating in 2012 with one of the highest scores by percentage of total points earned in any LEED category, making it one of the top ten greenest buildings in the world.^[160]

The Cashman Equipment building is the first construction equipment dealership to receive LEED certification. It is the largest LEED industrial complex in Nevada. Caterpillar corporate has rewritten their development guidelines for new facilities based on this building.^{[161][relevant?]}

Around 2010, the Empire State Building underwent a $550 million renovation, including $120 million towards energy efficiency and eco-friendliness.^[163] It received a gold LEED rating in 2011, and at the time was the tallest LEED-certified building in the United States.^[164]

Although originally constructed in 1973, Willis Tower a commercial office building located in Chicago, adopted and implemented a new set of sustainable practices in 2018, earning the property LEED Gold certification under the LEED for Existing Buildings: O&M™ rating system. This adoption brought Willis Tower to be the current tallest LEED-certified building in the United States.^[165]

The Coastal Maine Botanical Gardens Bosarge Family Education Center, completed in 2011, achieved LEED Platinum certification and became known as "Maine's greenest building".^[166]

In October 2011 Apogee Stadium at the University of North Texas became the first newly built stadium in the country to achieve Platinum-level certification.^[167] In May 2012, Soldier Field in Chicago became the first National Football League (NFL) stadium certified LEED.^[168] In July 2014, the San Francisco 49ers' Levi's Stadium became the first NFL venue to earn a LEED Gold certification. The Minnesota Vikings' U.S. Bank Stadium equaled this feat with a Gold certification in Building Design and Construction in 2017 as well as a Platinum certification in Operations and Maintenance in 2019, a first for any professional sports stadium.^[169]

In September 2012, The Crystal in London became the world's first building awarded LEED Platinum and BREEAM Outstanding status.^[170] 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.^[171]

When it received LEED Platinum in 2012, Manitoba Hydro Place in downtown Winnipeg was the most energy-efficient office tower in North America and the only office tower in Canada with a Platinum rating. The office tower employs south-facing winter gardens to capture solar energy during the harsh Manitoba winters and uses glass extensively to maximize natural light.^[172]

In San Francisco's Presidio, the Letterman Digital Arts Center earned a Gold certification. It was built almost entirely from the recycled remains of the Letterman Army Hospital, which previously occupied the site.^[173]

Torre Sul of Green Tower Brasilias received LEED Gold certification in 2014. In the public retail area on the first floor, visitors can see the largest green wall in Latin America, which is 197 feet (60 m) high.^[174]

In 2017,^[175] Kaiser Permanente, the largest integrated health system in the United States,^[55] opened California's first LEED Platinum certified hospital, the Kaiser Permanente San Diego Medical Center. By 2020, Kaiser Permanente owned 40 LEED certified buildings.^[175] Its construction of LEED buildings was one of multiple initiatives that enabled Kaiser Permanente to report net-zero carbon emissions in 2020.^[55]

As of 2023, University of California, Irvine currently has 32 LEED-certified (21 LEED Platinum and 11 LEED Gold) buildings across the campus. "UCI Sustainability".

Criticism

In 2005, Auden Schendler and Randy Udall, respectively a LEED-accredited professional who is the director of environmental affairs at the Aspen Skiing Company and a Colorado-based environmentalist, published an article titled "LEED is Broken; Let's Fix It", in which they criticized numerous aspects of the LEED certification process. They characterized as "costly, slow, brutal, confusing, and unwieldy ... that makes green building more difficult than it needs to be".^[176] Schendler and Udall also identify an environmentalist fallacy which they call "LEED brain", in which the public relations value of LEED certification begins to drive the development of buildings.^[177] Writer David Owen, in his book Green Metropolis, gives as an example of "LEED brain" the building by Gap Inc. of a green showcase building in San Bruno, California, that, in itself, was a paradigm of environmentally-friendliness, but by its location, 16 miles (26 km) from the company's corporate headquarters in downtown San Francisco, and 15 miles (24 km) from Gap's corporate campus in Mission Bay, was actually harmful to the environment by forcing Gap employees to drive more miles, and the addition of shuttle buses between the various buildings. Owen points out that "no bus is as green as an elevator".^[178]

In his book Walkable City, city planner Jeff Speck provides another example of "LEED brain": the federal Environmental Protection Agency relocated its Region 7 Headquarters from downtown Kansas City, Missouri, to a LEED-certified building 20 miles (32 km) away in the suburb of Lenexa, Kansas, causing many of the agency's 627 employees to drive additional miles to and from work. Kaid Benfield of the Natural Resources Defense Council estimated that the carbon emissions associated with the additional miles driven were almost three times higher than before, a change from 0.39 metric tons per person per month to 1.08 metric tons of carbon dioxide per person per month. Speck writes that "The carbon saved by the new building's LEED status, if any, will be a small fraction of the carbon wasted by its location".^[179]

Both Speck and Owen make the point that a building-centric standard such as LEED, which doesn't sufficiently account for the location in which the building stands, will inevitably undervalue the strong positive effect of people living closer together in cities, which are inherently environmentally efficient, especially when compared to the automobile-oriented sprawl.^[179][180]

LEED standards have also been criticized for not actually creating energy efficient buildings. In 2013, The Washington Examiner analyzed energy efficiency data of New York City buildings and found that LEED-certified buildings actually performed worse than buildings in general.^[181] An analysis by USA Today found that building makers target LEED's easiest points – those that don't necessarily increase the energy efficiency of a building.^[9]