Passive house (German: Passivhaus) is a voluntary standard for energy efficiency in a building that reduces the building's carbon footprint. Conforming to these standards results in ultra-low energy buildings that require less energy for space heating or cooling. A similar standard, MINERGIE-P, is used in Switzerland. Standards are available for residential properties, and several office buildings, schools, kindergartens and a supermarket
have also been constructed to the standard. Energy efficiency is not an
attachment or supplement to architectural design, but a design process
that integrates with architectural design. Although it is generally applied to new buildings, it has also been used for renovations.
In 2008, estimates of the number of passive house buildings around the world ranged from 15,000 to 20,000 structures. In 2016, there were approximately 60,000 such certified structures of all types worldwide. The vast majority of passive house structures have been built in German-speaking countries and Scandinavia.
History
Bo Adamson, co-originator of the passive house concept
Wolfgang Feist, co-originator of the passive house concept, and founder of the Passivhaus-Institut in Germany
The term passive house has had at least two meanings in the
literature. Its earlier meaning, used since the 1970s, was for a
low-energy building designed to exploit passive solar technologies and
establish a comfortable indoor temperature with a low-energy requirement
for heating or cooling. More recently the term has been used to
indicate a building that is certified to meet the criteria for the
passive house standard, including heating, cooling and primary energy
demands in addition to airtightness, thermal comfort requirements and
non-heating related energy demands.
The passive house standard originated from a conversation in May 1988 between Bo Adamson of Lund University, in Sweden, and Wolfgang Feist of the Institut für Wohnen und Umwelt (Institute for Housing and Environment), in Darmstadt, Germany. Their concept was developed through a number of research projects with financial assistance from the German state of Hesse.
Many of the early passive house builds were based on research and
the experience of North American builders during the 1970s, who—in
response to the OPEC oil embargo—sought to build homes that used little to no energy. These designs often utilised expansive solar-gain windows, which used the sun as a heat source. However, superinsulation became a key feature of such efforts, as seen in the Saskatchewan Conservation House in Regina, Saskatchewan, (1977) and the Leger House in Pepperell, Massachusetts (1977). The Saskatchewan Conservation House was a project of the Saskatchewan Research Council (SRC) with Harold Orr as its lead engineer.
The team independently developed a heat recovery air exchanger, hot
water recovery, and a blower-door apparatus to measure building
air-tightness. Notably, the house was designed for the extreme −40°C to +40°C climate of the Canadian Prairies. The SRC and Leger houses were predated by the Lyngby, Denmark house (1975), developed by the Technical University of Denmark, and several homes were built between 1977 and 1979 based on the Lo-Cal house design (1976) developed by the University of Illinois at Urbana–Champaign.
The term passive can be partly attributed to William Shurcliff, an American physicist who contributed to the WWII Manhattan Project, and in the 1970s became an advocate for energy-efficient home design:
What name should be given to this
new system? Superinsulated passive? Super-save passive? Mini-need
passive? Micro-load passive? I lean toward ‘micro-load passive.’
Whatever it is called, it has (I predict) a big future.
— William Shurcliff,
An early book explaining the concepts of passive house construction was The Passive Solar Energy Book by Edward Mazria in 1979.
First examples
The eventual construction of four row houses (terraced houses or town homes) were designed for four private clients by the architectural firm Bott, Ridder and Westermeyer. The first passive house residences were built in Darmstadt in 1990, and occupied the following year.
In September 1996, the Passivhaus-Institut
was founded in Darmstadt to promote and control passive house
standards. By 2010 more than 25,000 passive house structures were
estimated to have been built. Most are located in Germany and Austria, others in various countries worldwide.
In 1996, after the concept had been validated at the Institute in
Darmstadt, with space heating at 90% less than that required for a
standard new building at the time, the economical passive houses working
group was created. This group developed the planning package and
initiated the production of the innovative components that had been
used, notably the windows and the high-efficiency ventilation systems.
Meanwhile, further passive houses were built in Stuttgart (1993), Naumburg, Hesse, Wiesbaden, and Cologne (1997).
Products that had been developed according to the passive house standard were further commercialized during and following the European Union sponsored CEPHEUS project, which proved the concept in five European countries in the winter of 2000–2001. The first certified house was built in 2006 near Bemidji, Minnesota, in Camp Waldsee of the German Concordia Language Villages. The first US passive retrofit project, the remodeled craftsman O'Neill house in Sonoma, California, was certified in July 2010.
In the United States, passive house design was first implemented
by Katrin Klingenberg in 2003 when she built a passive home prototype
named "The Smith House" in Urbana, Illinois.
Later, she and builder Mike Kernagis co-founded the Ecological
Construction Laboratory in 2004 to further explore the feasibility of
the affordable passive design. It eventually led to the inception of the Passive House Institute United States (PHIUS) in 2007.
Afterwards, the PHIUS has released their PHIUS + 2015 Building Standard
and has certified over 1,200 projects and 1.1 million square feet
(100,000 m2) across the United States.
In 2019, Park Avenue Green, a low-income housing building in New York
was built with passive house standards. The building later became the
largest certified passive house in North America.
Ireland's first passive house
was built in 2005 by Tomas O'Leary, a "passive house" designer and
teacher. The house was called 'Out of the Blue'. Upon completion, Tomas
moved into the building.
The first certified passive house in Antwerp, Belgium, was built in 2010. In 2011, Heidelberg, Germany, initiated the Bahnstadt project, which was seen as the world's largest passive house building area. A company in Qatar planned the country's first Passive House in 2013, the first in the region.
The world's tallest passive house was built in the Bolueta neighborhood in Bilbao, Spain.
At 289 feet (88 m), it is currently the world's tallest building
certified under the standard in 2018. The $14.5 million, 171-unit
development (including a nine-story companion to the high-rise) consists
entirely of social housing.
Gaobeidian,
China, hosted the 23rd International Passive House Conference in 2019,
and later built the Gaobeidian Railway City apartment complex which is
reported to be "the world's largest passive house project". China has 73 different companies that have started "making windows to the 'passive house' standards."
The United Kingdom’s first passive house health centre in Foleshill was opened in November 2021.
Standards
The dark colours on this thermogram of a Passive house, at right, shows how little heat is escaping compared to a traditional building to the left.
While some techniques and technologies were specifically developed for the passive house standard, others, such as superinsulation, already existed, and the concept of passive solar building design dates back to antiquity. There were other previous buildings with low-energy building standards, notably the German Niedrigenergiehaus (low-energy house) standard, in addition to buildings constructed to the demanding energy codes of Sweden and Denmark.
International passive house standard
The passive house standard requires that the building fulfills the following requirements:
Use up to 15 kWh/m2 (4,755 BTU/sq ft; 5.017 MJ/sq ft)
of floor area per year for heating and cooling as calculated by the
Passivhaus Planning Package, or a peak heat load of 10 W/m2 (1.2 hp/1000 sq ft) of floor area based on local climate data.
Leak air up to 0.6 times the house volume per hour (n50 ≤ 0.6 / hour) at 50 Pa (0.0073 psi) as tested by a blower door; or up to 0.05 cubic feet per minute (1.4 L/min) per square foot of the surface area of the enclosure.
Recommendations
The specific heat load for the heating source at design temperature is recommended, but not required, to be less than 10 W/m2 (3.17 btu/(h⋅ft2)).
National partners within the 'consortium for the Promotion of
European Passive Houses' are thought to have some flexibility to adapt
these limits locally.
Passive house standards in the US - Passive House Standard and PHIUS+
In
the US there are two versions of passive house being promoted by two
separate entities: the Passive House Institute (PHI) and the Passive
House Institute US (PHIUS).
PHIUS was originally an affiliate and approved trainer and
certifier for the Passive House Institute. In 2011, PHI cancelled its
contract with PHIUS for misconduct. PHIUS disputed the claims by PHI and continued working to launch an independent building performance program.
In 2015 PHIUS launched its own PHIUS+ standard, which primarily
focuses on reducing negative effects of building operations for any type
of building. This standard also uses climate data sets to determine
specific building performance criteria for different regions. Such information is determined using metrics that represent a space where significant carbon and energy reduction overlap with cost-effectiveness. Overall, the PHIUS database includes more than 1,000 climate data sets for North America.
The standard is based on five principles: airtightness, ventilation, waterproofing, heating and cooling, and electrical loads. Within these principles, projects must pass building specified blower door, ventilation airflow, overall airflow, and electrical load
tests; buildings must also achieve other measures such as low-emission
materials, renewable energy systems, moisture control, outdoor
ventilation, energy efficient ventilation and space conditioning
equipment. All buildings must also pass a quality assurance and quality control
test – this is implemented to ensure that the building continues to
adhere to the regional criteria set forth by the PHIUS’ climate data.
These tests and analyses of operative conditions are performed by PHIUS
raters or verifiers. These are accredited professionals from the PHIUS
that are able to perform on-site testing and inspections to ensure that
the newly constructed building is adhering to the construction plans,
created energy models, and desired operating conditions.
The two standards (passive house and PHIUS+) are distinct and
target different performance metrics and use different energy modeling
software and protocols.
Construction costs
In
passive house buildings, the cost savings from replacing the
conventional heating system can be used to fund the upgrade of the
building envelope and the heat recovery ventilation system. With careful
design and increasing competition in the supply of the specifically
designed passive house building products, in Germany it is currently
possible to construct buildings for the same cost as those built to
normal German building standards, as was done with the passive house apartments in Vauban, Freiburg. On average, passive houses are reported to be more expensive upfront than conventional buildings: 5% to 8% in Germany,8% to 10% in UK and 5% to 10% in USA.
Evaluations have indicated that while it is technically possible,
the costs of meeting the passive house standard increase significantly
when building in Northern Europe above 60° latitude.
Design and construction
The Passivhaus uses a combination of low-energy building techniques and technologies.
Achieving the major decrease in heating energy consumption required
by the standard involves a shift in approach to building design and
construction. Design may be assisted by use of the Passivhaus Planning
Package (PHPP), which uses specifically-designed computer simulations.
Below are the techniques used to achieve the standard.
Passive solar design and landscape
Passive solar building design and energy-efficient landscaping support passive house energy conservation and can integrate them into a neighborhood and environment. Following passive solar building techniques,
where possible buildings are compact in shape to reduce their surface
area; principal windows are oriented towards the equator to maximize
passive solar gain. However, the use of solar gain, especially in temperateclimate
regions, is secondary to minimizing the overall house energy
requirements. In climates and regions needing to reduce excessive summer
passive solar heat gain, whether from direct or reflected sources, brise soleil, trees, attached pergolas with vines, vertical gardens, green roofs, and other techniques are implemented.
Exterior wall color, when the surface allows a choice for reflection or absorption insolation qualities, depends on the predominant year-round ambient outdoor temperature. The use of deciduous trees and wall trellised or self attaching vines can assist in climates not at the temperature extremes.
Superinsulation
Passive house buildings employ superinsulation to significantly reduce the heat transfer through the walls, roof and floor compared to conventional buildings. A wide range of thermal insulation materials can be used to provide the required high R-values (low U-values, typically in the 0.10 to 0.15 W/(m2·K) range). Special attention is given to eliminating thermal bridges.
Advanced window technology
Typical passive-house windows
To meet the requirements of the passive house standard, windows are manufactured with exceptionally high R-values (low U-values, typically 0.85 to 0.45 W/(m2·K) for the entire window including the frame). The windows normally combine triple or quadruple-pane insulated glazing (with an appropriate solar heat-gain coefficient. low-emissivity coatings, sealedargon or krypton
gas filled inter-pane voids, and 'warm edge' insulating glass spacers)
with air-seals and specially developed thermal break window frames.
Air tightness
Building envelopes under the passive house standard are required to be extremely airtight
compared to conventional construction. They are required to meet 0.60
ACH50 (air changes per hour at 50 pascals) based on the building's
volume. In order to achieve these metrics, best practice is to test the
building air barrier enclosure with a blower door at mid-construction if possible.
A passive house is designed so that most of the air exchange with exterior is done by controlled ventilation through a heat-exchanger in order to minimize heat loss (or gain, depending on climate), so uncontrolled air leaks are best avoided. Another reason is the passive house standard makes extensive use of insulation which usually requires a careful management of moisture and dew points.
This is achieved through air barriers, careful sealing of every
construction joint in the building envelope, and sealing of all service
penetrations.
Ventilation
Use of passive natural ventilation
is an integral component of passive house design where ambient
temperature is conducive – either by singular or cross-ventilation, by a
simple opening, or enhanced by the stack effect from smaller ingress with larger egress windows and/or clerestory-operable skylight.
When ambient climate is not conducive, mechanical heat recovery ventilation systems with a heat recovery rate of over 80% and high-efficiency electronically commutated motors
(ECM) are employed to maintain air quality, and to recover sufficient
heat to dispense with a conventional central heating system. Since passively designed buildings are essentially air-tight, the rate of air change can be optimized and carefully controlled at about 0.4 air changes per hour. All ventilation ducts are insulated and sealed against leakage.
Some passive house builders promote the use of earth warming tubes.
The tubes are typically around 200 millimetres (7.9 in) in diameter, 40
metres (130 ft) long at a depth of about 1.5 metres (4.9 ft). They are
buried in the soil to act as earth-to-air heat exchangers and pre-heat
(or pre-cool) the intake air for the ventilation system. In cold
weather, the warmed air also prevents ice formation in the heat recovery system's heat exchanger. Concerns about this technique have arisen in some climates due to problems with condensation and mold.
Space heating
In
addition to the heat exchanger (centre), a micro-heat pump extracts
heat from the exhaust air (left) and hot water heats the ventilation air
(right). The ability to control building temperature using only the
normal volume of ventilation air is fundamental.
In addition to using passive solar gain, passive house buildings make extensive use of their intrinsic heat from internal sources—such as waste heat from lighting, major appliances
and other electrical devices (but not dedicated heaters)—as well as
body heat from the people and other animals inside the building. This is
due to the fact that people, on average, emit heat equivalent to 100 watts each of radiated thermal energy.
Together with the comprehensive energy conservation measures taken, this means that a conventional central heating system is not necessary, although they are sometimes installed due to client's skepticism.
Instead, passive houses sometimes have a dual purpose 800 to 1,500 watt
heating and/or cooling element integrated with the supply air duct of
the ventilation system, for use during the coldest days. It is
fundamental to the design that all the heat required can be transported
by the normal low air volume required for ventilation. A maximum air
temperature of 50 °C (122 °F) is applied, to prevent any possible smell
of scorching from dust that escapes the filters in the system.
Beyond the recovery of heat by the heat recovery ventilation
unit, a well-designed passive house in the European climate should not
need any supplemental heat source if the heating load is kept under 10
W/m2.
The passive house standards in Europe set a space heating and cooling energy demand of 15 kWh/m2 (4,750 BTU/sq ft) per year, and 10 W/m2
(3.2 Btu/h/sq ft) peak demand. In addition, the total energy to be used
in the building operations including heating, cooling, lighting,
equipment, hot water, plug loads, etc. is limited to 120 kWh/m2 (38,000 BTU/sq ft) of treated floor area per year.
Traits of passive houses
Some
have voiced concerns that the passive house standard is not a general
approach as the occupant has to behave in a prescribed way; for example,
not opening windows too often. A 2013 study concluded that in general
passive houses are less sensitive to such behaviour than anticipated.
International comparisons
In the United States, a house built to passive house standard results in a building that requires space heating energy of 1 British thermal unit per square foot (11 kJ/m2) per heating degree day, compared with about 5 to 15 BTU/sq ft (57 to 170 kJ/m2)
per heating degree day for a similar building built to meet the 2003
Model Energy Efficiency Code. This is between 75 and 95% less energy for
space heating and cooling than current new buildings that meet today's
US energy efficiency codes. The passive house in the German-language
camp of Waldsee,
Minnesota, was designed by architect Stephan Tanner of INTEP, LLC, a
Minneapolis- and Munich-based consulting company for high performance
and sustainable construction. Waldsee BioHaus is modeled on Germany's
passive house standard and, when compared to houses of the U.S. LEED
standard, shows improvement to the quality of life inside the building
while using 85% less energy than a house built to the latter standard. VOLKsHouse 1.0 was the first certified "passive house" offered and sold in Santa Fe New Mexico.
In the United Kingdom,
an average new house built with the passive house standard used 77%
less energy for space heating compared to the house built under
circa-2006 Building Regulations.
In Ireland,
a typical house built to passive house standards instead of to the 2002
Building Regulations consumed 85% less energy for space heating and cut
space-heating related carbon emissions by 94%.
Taipei 101 has achieved LEED Platinum certification three times, as of 2021.Washington, D.C., is the first LEED Platinum city in the world. Pictured is 1225 Connecticut Avenue, the first redeveloped office building on the U.S. East Coast to receive LEED Platinum status.
Leadership in Energy and Environmental Design (LEED) is a green building certification program used worldwide. 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 2024 there were over 195,000 LEED-certified buildings and over 205,000 LEED-accredited professionals in 186 countries worldwide.
In the US, the District of Columbia consistently leads in LEED-certified square footage per capita, followed in 2022 by the top-ranking states of Massachusetts, Illinois, New York, California, and Maryland.
Outside the United States, the top-ranking countries for 2022 were Mainland China, India, Canada, Brazil, and Sweden.
LEED Canada has developed a separate rating system adapted to the Canadian climate and regulations.
Many U.S. federal agencies, state and local governments require or reward LEED certification. As of 2022, based on certified square feet per capita, the leading five states (after the District of Columbia) were Massachusetts, Illinois, New York, California, and Maryland.
Incentives 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%).
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 tended to focus on energy modeling rather than actual energy
consumption.
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; for lacking climate specificity; for not sufficiently addressing issues of climate change and extreme weather; and for not incorporating principles of a circular economy.
Draft versions of LEED v5 were released for public comment in 2024, and
the final version of LEED v5 is expected to appear in 2025. It may address some of the previous criticisms.
Despite concerns, LEED has been described as a "transformative force in the design and construction industry".
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.
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.
Also influential early on was architect Bob Berkebile.
Shearer's Foods plant in Massillon, Ohio, was the first food manufacturing plant to receive LEED Platinum status in 2009.
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.Ramanujam served as CEO until 2021. Peter Templeton became interim president and CEO of USGBC as of November 1, 2021.
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. It was Watson, sometimes referred to as the "Founding Father of LEED", who created the acronym.
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), architect Sandy Mendler, builder Gerard Heiber and engineer Richard Bourne.
Tom Paladino and Lynne Barker (formerly King) co-chaired the LEED Pilot Committee from 1996–2001.
Scot Horst chaired the LEED Steering Committee beginning in 2005 and was deeply involved in the development of LEED 2009.
Joel Ann Todd took over as chair of the steering committee from 2009 to 2013, working to develop LEED v4, and introducing social equity credits.
Other steering committee chairs include Chris Schaffner (2019) and Jennifer Sanguinetti (2020).
Chairs of the USGBC's Energy and Atmosphere Technical Advisory Group for LEED technology have included Gregory Kats.
The LEED initiative has been strongly supported by the USGBC Board of Directors, including
Chair of the Board of Directors Steven Winter (1999–2003). The current chair of the Board of Directors is Anyeley Hallová (2023).
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.
As of 2023, more than 185,000 LEED projects representing over 28 billion square feet (2.6×109 m2) have been proposed worldwide, and more than 105,000 projects representing over 12 billion square feet (1.1×109 m2) have been certified in 185 countries.
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. LEED is considered a target of a type of disinformation attack known as astroturfing, involving "fake grassroots organizations usually sponsored by large corporations".
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.
Rating systems
LEED
has evolved since 1998 to more accurately represent and incorporate
emerging green building technologies. LEED has developed building
programs specific to new construction (NC), core and shell (CS),
commercial interiors (CI), existing buildings (EB), neighborhood
development (ND), homes (LEED for Homes), retail, schools, and
healthcare.
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. LEED v4.1 was released on April 2, 2019.
Draft versions of LEED v5 have been released and revised in
response to public comment during 2024. The official final version of
LEED v5 is expected to be released in 2025. Future updates to the
standard are planned to occur every five years.
LEED 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).
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:
Green building design and construction (BD+C) – for new construction, core and shell, 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
LEED v3 aligned credits across all LEED rating systems, weighted by environmental priority. 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 (SS), water efficiency (WE), energy and atmosphere (EA), materials and resources (MR), indoor environment quality
(IEQ) and design innovation (INNO). 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, and the need for
buildings and settlements to educate occupants.
Shanghai Tower, the tallest and largest LEED Platinum certified building in the world since 2015.
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) 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 minimum requirements including 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).
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.
The LEED council also appears to have assigned credit and
measured weighting based upon the market implications of point
allocation.
From 2010, buildings can use carbon offsets to achieve green power credits for LEED-NC (new construction certification).
LEED v4 (2014)
For LEED BD+C v4 credit, the IEQ category addresses thermal, visual, and acoustic comfort as well as indoor air quality.
Laboratory and field research have directly linked occupants'
satisfaction and performance to the building's thermal conditions.
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.
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.However, LEED v4.1 was never officially balloted.
An update to v4, proposed as of November 22, 2022, took effect on
March 1, 2024. Any projects that register under LEED v4 after March 1,
2024 must meet these updated guidelines.
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. The LEED v5 rating system will cover both new construction and existing buildings.
An initial draft version was discussed at Greenbuild 2023. The beta draft of LEED v5 was released for an initial period of public comment on April 3, 2024.
Changes were made in response to nearly 6,000 comments. A second
public comment period was opened for the revised version, from September
27 to October 28, 2024.
The official release of the final version of LEED v5 is expected to
occur in 2025. Future updates of the certification system are planned to
occur every five years.
LEED v5 reorganizes the credits system and prerequisites, and has
a greater focus on decarbonization of buildings. 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.
One of the reponses to public comments was to emphasize a data-driven
approach to Operations and Maintenance by more clearly identifying
performance-based credits (80% of points) and decoupling them from
strategic credits (20%).
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.
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. 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.
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, and Investor Ready Energy Efficiency (IREE). IREE is a model supported by CAGBC and the Canada Infrastructure Bank (CIB) for the verification of proposed retrofit projects.
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.
"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.
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.
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 when considering design decisions.
LEED for Homes rating system
The LEED for Homes rating system was first piloted in 2005. It has been available in countries including the U.S., Canada, Sweden, and India. LEED for Homes projects are low-rise residential.
The process of the LEED for Homes rating system differs significantly from the LEED rating system for new construction. Unlike LEED, LEED for Homes requires an on-site inspection. LEED for Homes projects are required to work with either an American or a Canadian provider organization
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. The provider and rater assist in the certification process but do not themselves certify the project.
Professional accreditation
In addition to certifying projects pursuing LEED, 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.
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."
Criticism
Critics of LEED certification such as Auden Schendler
and Randy Udall have pointed out that the process is slow, complicated,
and expensive. In 2005, they published an article titled "LEED is
Broken; Let's Fix It", in which they argued that the certification
process "makes green building more difficult than it needs to be" and
called for changes "to make LEED easier to use and more popular" to
better accelerate the transition to green building.
Schendler and Udall also identified a pattern which they call
"LEED brain", in which participants may become focused on "point
mongering" and pick and choose design elements that don't actually go
well together or don't fit local conditions, to gain points. The public
relations value of LEED certification begins to drive the development of
buildings rather than focusing on design. 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.
A 2012 USA Today
review of 7,100 LEED-certified commercial buildings found that
designers tended to choose easier points such as using recycled
materials, rather than more challenging ones that could increase the
energy efficiency of a building.
Critics such as David Owen
and Jeff Speck also point out that LEED certification focuses on the
building itself, and does not take into account factors such as the
location in which the building stands, or how employee commutes may be
affected by a relocation. In Green Metropolis (2009), Owen discusses an environmentally-friendly building in San Bruno, California, built by Gap Inc., which was located 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. Although the company added shuttle buses between buildings, "no bus is as green as an elevator". Similarly, in Walkable City (2013), Jeff Speck describes the relocation of the Environmental Protection Agency's Region 7 Headquarters from downtown Kansas City, Missouri, to a LEED-certified building 20 miles (32 km) away in the suburb of Lenexa, Kansas. 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".
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.
Assessment
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.
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, and concerns about the accuracy of its predictive models.
Research papers provide most of what is known about the
performance and effectiveness of LEED models and buildings. 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. Research papers have
tended to address performance and effectiveness of LEED in two credit
category areas: energy (EA) and indoor environment quality (IEQ).
Many early analyses should be considered as at best 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 and certification levels of individual
buildings. Buildings may also need to be grouped according to location,
since local conditions and regulation may influence building design and
confound assessment results.
Modelling assessment
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%). Energy and Atmosphere (EA) was intermediate (60–65%) in
northern Europe, and low (40%) in southern Europe. These results examine
the extent to which different credits have been chosen by modellers.
Energy performance research (EA)
Because
LEED focuses on the design of the building and not on its actual energy
consumption, 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.
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.
The data included only "medium use" buildings, and did not include 21
laboratories, data centers and supermarkets which were expected to have
higher energy activity. Researchers further attempted to match each
building with a conventional building within the Commercial Building
Energy Consumption Survey (CBECS) database according to building type
and occupancy.
On average, the LEED buildings consumed 18 to 39% less energy by floor
area than the conventional buildings. However, 28 to 35% of
LEED-certified buildings used more energy.
The paper found no correlation between the number of energy points
achieved or LEED certification level and measured building performance.
The Hostal Empúries was the first LEED (LEED Gold) certified hotel in Europe
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.
Scofield criticized the earlier analysis for focusing on energy per
floor area instead of a total energy consumption. Scofield considered
source energy (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. 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.
Scofield notes the difficulties of building analysis, given both
the lack of a randomly selected sample of LEED buildings, and the
diversity of factors involved when selecting a comparison group of
non-LEED buildings. In 2013 Scofield identified 21 LEED-certified New
York City office buildings with publicly available energy performance
data for 2011, out of 953 office buildings in New York City with such
data.
Results differed with certification level. LEED-Gold buildings were
found to use 20% less source energy than conventional buildings.
However, buildings at the Silver and Certified levels used 11 to 15%
more source energy, on average, than conventional buildings. (Data was
not available for Platinum-level buildings.)
An analysis of 132 LEED buildings based on municipal energy
benchmarking data from Chicago in 2015 showed that LEED-certified
buildings used about 10% less energy on site than comparable
conventional buildings. However, the study did not show differences in
use of source energy.
In 2014, architect Gwen Fuertes and engineer Stefano Schiavon 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 and 429 LEED-NC
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.
In a 2019 review, Amiri et al. suggest that judging energy
efficiency based on source energy may not be appropriate where the
availability of energy types depends on city council or government
policies. If some types of source energy are not supported locally,
there is no opportunity to choose the types of energy promoted by the
LEED scoring system. Amiri emphasizes that many studies have weaknesses
due to the lack of randomly selected samples of LEED buildings, and the
difficulty of selecting comparison groups of non-LEED buildings. Amiri
also notes that the standards for building design have changed
significantly over time. For example, newer non-LEED buildings may
routinely use features such as high-quality windows which were rarely
used in older buildings. 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.
Zhang et al. (2019) examined renewable energy assessment methods
and different assessment systems, and noted that LEED-US addresses
management problems at the pre-occupancy phase. Interest in Post‐occupancy evaluation
(POE), the process of evaluating building performance after occupation,
is increasing. This is due in part to concerns about differences
between energy models in the design phase and actual use of buildings.
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.
Asensio and Delmas (2017) carefully matched and compared
buildings that did and did not participate in LEED, Energy Star, and
Better Buildings Challenge programs in Los Angeles, California. They
examined data for monthly energy consumption between 2005–2012, for more
than 175,000 commercial buildings. Buildings from all three programs
displayed “high magnitude” energy savings, ranging from 18–19% for
Better Buildings and Energy Star to 30% for LEED-rated buildings. The
three programs saved 210 million kilowatt-hours, equal to 145 kilotons
of CO2 equivalent emissions per year.
IEQ performance research (IEQ)
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." 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.
The most widely used method for post-occupancy evaluation (POE) in IEQ-related studies is occupant surveys.
In 2013, architectural physicist Sergio Altamonte and Stefano Schiavon
used occupant surveys from the Center for the Built Environment at
Berkeley's database
to study IEQ occupant satisfaction in 65 LEED buildings and 79 non-LEED
buildings. They analyzed 15 IEQ-related factors including 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. Occupants reported being
slightly more satisfied in LEED buildings for the air quality and
slightly more dissatisfied with the amount of light. Overall, occupants
of both LEED and non-LEED buildings had equal satisfaction with the
building overall and with the workspace.
The authors noted that the data may not be representative of the entire
building stock and a randomized approach was not used in the data
assessment.
Newsham et al (2013) carried out an evaluation using both occupant interviews and physical site measurements.
Field studies and post-occupancy evaluations (POE) were performed in 12
"green" and 12 conventional buildings across Canada and the northern
United States. Most but not all of the "green" buildings were
LEED-certified. 2545 occupants completed a questionnaire. On-site, 974
randomly selected 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 green buildings were rated more highly and in the case
of airborne particulates exhibited superior performance than the
conventional buildings.
Schiavon and Altomonte (2014)
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.
This study suggests that the positive value of LEED certification as
measured by occupant satisfaction may decrease with time.
In 2015, environmental health scientist Joseph Allen (et al.)
reviewed studies of indoor environmental quality and the potential
health benefits of green-certified buildings. He concluded that green
buildings provide better indoor environmental quality with direct
benefits to the human health of occupants, compared to non-green
buildings. Statistically significant measures from different studies
included decreased symptoms of sick building syndrome, decreased sick
days, decreased respiratory symptoms during the daytime and asthma
symptoms at night, and lowered levels of PM2.5, NO2,
and nicotine. However, Allen noted that the frequent use of subjective
health performance indicators was a limitations of many of the studies
reviewed. He proposed a framework to encourage the use of direct,
objective, and leading “Health Performance Indicators” in building
assessment.
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. 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.).
In 2024, Kent et al. compared satisfaction of people in buildings that had received either WELL certification
or LEED certification. Ratings of buildings certified with WELL and
LEED were matched on six dimensions: award level, years in building,
time in workspace, type of workspace, proximity to a window, and floor
height. Satisfaction with the overall building and one's workspace were
high under both rating systems. However, satisfaction with
LEED‑certified buildings (73% and 71%) tended to be lower than that for
WELL‑certified buildings (94% and 87%). This may be because WELL is a
human-centered standard for building design that focuses primarily on
comfort, health, and well-being. In contrast, only 10% of the credits in
LEED certification relate to indoor environmental quality (IEQ).
Differences may also reflect age of buildings, which were not matched
for in the design.
Water Efficiency (WE)
Water
systems involve both water and energy as resources. Outside buildings,
the acquisition, treatment, and transportation of water is involved.
Inside building, onsite water treatment, heating, and wastewater
treatment are issues. Data on the energy use of specific water and
wastewater systems is becoming increasingly available. Energy use can
sometimes be estimated from public sources. LEED v4 includes a number of
credits related to Water Efficiency (WE). Points are awarded for
Outdoor Water Use Reduction, Indoor Water Use Reduction and
Building-level Water Metering based on predetermined percentage
reductions in water or energy use.
There has been criticism that the LEED rating system is not
sensitive and does not vary enough with regard to local environmental
conditions. For example, there are 16 climate zones in California,
with unique weather and temperature patterns. The availability of
electricity, water and other resources differs widely in different
regions, making it important to consider interconnected systems and
supply chain issues. Greer et al. (2019) reviewed renewable energy
assessment methods and examined the effectiveness of LEED v4 buildings
in California. They examined relationships between the climate
mitigation points given for water efficiency (WE) and energy efficiency
(EA) and used baseline energy and water budgets to calculate the avoided
GHG
emissions of buildings. Their calculations both demonstrate mitigation
of expected climate change and also indicate high variability in
environmental outcomes within the state.
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. They report that
impacts like the mitigation of expected climate change pollution can be
calculated, and while "LEED points do not equally reward equal impact
mitigation", such differences could be reconciled to better align LEED
credits and goals.
Innovation in design research (ID)
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.
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. 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.
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. VOC released from construction materials into the air is another challenge to address.
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. Similar concepts are under development elsewhere, with considerable market potential.
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 as part of the Urban Transformation Project of the Kartal port region.
Sustainable Sites (SS)
Remaining credit areas
Other credit areas include:
Materials and Resources (MR), and
Regional Priority (RP).
Financial considerations
When
a LEED rating is pursued, the cost of initial design and construction
may rise. 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.
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.
Real estate developers have begun to use LEED certification and a building's green status as selling points.
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.
From a financial perspective, studies from 2008 and 2009 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.
More recent studies have confirmed earlier findings that certified
buildings achieve significantly higher rents, sale prices and occupancy
rates as well as lower capitalization rates, potentially reflecting
lower investment risk.
Incentive programs
Many
federal, state, and local governments and school districts have adopted
various types of LEED initiatives and incentives. LEED incentive
programs 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.
Beginning in June 2013, USGBC has offered free LEED certification
to the first LEED-certified project in a country that doesn't have
one.
Notable certifications
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.
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.
A number of sites including the Canada Green Building Council (CaGBC) Project Database list resources relating to LEED buildings in Canada.
Platinum certification
The Philip Merrill Environmental Center
The Philip Merrill Environmental Center
in Annapolis, Maryland 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.
The first LEED platinum-rated building outside the U.S. is the
CII Sohrabji Godrej Green Business Centre (CII GBC) in Hyderabad, India, certified in 2003 under LEED version 2.0.
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.
Sota Construction Corporate Headquarters in Pittsburgh earned LEED Platinum in 2012.
In Pittsburgh, Sota Construction Services' corporate headquarters
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. It featured a
super-efficient thermal envelope using cob walls, a geothermal well, radiant heat flooring, a roof-mounted solar panel array, and daylighting features.
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.
Gold certification
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.
It earned Platinum certification in 2012, becoming the only convention
center with certifications for both the original building and new
construction.
The Cashman Equipment building in Henderson, Nevada became the
first construction equipment dealership to receive LEED gold
certification in 2009. The headquarters of the Caterpillar brand, it is
the largest LEED industrial complex in Nevada.
The Empire State Building
in New York City is one of the tallest and most well-known
LEED-certified buildings, certified as an LEED Gold existing building.
Around 2010, the Empire State Building underwent a $550 million renovation, including $120 million towards energy efficiency and eco-friendliness. It received a gold LEED rating in 2011, and at the time was the tallest LEED-certified building in the United States.
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.
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 earned Willis Tower the ranking of the
tallest LEED-certified building in the United States.
In September 2012, The Crystal in London became the world's first building awarded LEED Platinum and BREEAM Outstanding status. 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.
In Pittsburgh, the visitor's center of Phipps Conservatory & Botanical Gardens received Silver certification, its Center for Sustainable Landscapes received a Platinum certification and fulfilled the Living Building Challenge for net-zero energy,
and its greenhouse facility received Platinum certification. It may be
the only greenhouse in the world to have achieved such a rating.
Torre Mayor, Mexico
Torre Mayor, at one time the tallest building in Mexico, achieved LEED Gold certification for an existing building and eventually reached Platinum certification under LEED v4.1.
The building is designed to withstand 8.5-magnitude earthquakes, and
has enhanced many of its systems including air handling and water
treatment.
In 2017, Kaiser Permanente, the largest integrated health system in the United States,
opened California's first LEED Platinum certified hospital, the Kaiser
Permanente San Diego Medical Center. By 2020, Kaiser Permanente owned 40
LEED certified buildings.
Its construction of LEED buildings was one of multiple initiatives that enabled Kaiser Permanente to report net-zero carbon emissions in 2020.
As of 2022, University of California, Irvine had 32 LEED-certified buildings across the campus. 21 were LEED Platinum certified, and 11 were LEED Gold.
Extreme structures
Extreme structures that have received LEED certification include: Amorepacific Headquarters in Seoul by David Chipperfield Architects; Project: Brave New World: SFMOMA by Snøhetta in San Francisco, California; Project: UFO in a Sequinned Dress: Centro Botín in Santander by Renzo Piano; Building Workshop in Zusammenarbeit with Luis Vidal + Architects, in Santander, Spain; and Project: Vertical factory: Office building in London by Allford Hall Monaghan Morris in London.
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