Green Synergies

Introduction         

If you follow sustainable design news – or really any architecture-related news – you will have heard of LEED. LEED certified buildings seem to pop up everywhere, especially in the rarefied domains of government, education and high-end real estate development.

And you know what LEED is: LEED stands for Leadership in Energy and Environmental Design, and it is a sustainable rating system – the most widely used sustainable rating system in the world. It is developed by the US Green Building Council (USGBC), a non-profit organization, and administered by Green Business Certification Inc. (GBCI). It has four certification levels: Certified, Silver, Gold and Platinum.

But what does it really mean for a building to be LEED certified? How did LEED come to be, how is the system organized and how do buildings get certified? Without going deep into the complexities of the LEED credit library, how does LEED translate sustainable objectives and design into a neat point-based rating system that eventually results in a shiny plaque decorating the lobby wall of a new building?

This post will answer those questions and more besides, so that you can better understand what LEED means in a world in which sustainability is of increasing importance to designers, policy makers and business leaders, and in which understanding sustainability has become part of the mental portfolio of an educated person. Understanding LEED more deeply will help you to understand the discourse around sustainability so that you can engage in this discourse, educate others and ultimately make better decisions about what gets built.

Context

Since the 1960s, environmentalism had developed from a niche concern into a matter of public policy that has transformed industries and deeply affected the way we live, often very much for the better. Environmental protection was initially concerned with mitigating the effects of human activities on the natural world, but in recent decades the concept of environmental protection has morphed into the holistic concept of sustainability, which has become a meta-concept for design, business and public policy in the early twenty-first century. Sustainability is a moral attitude that pursues the mutual long-term benefit of human civilization, the natural environment in which we live, and the economy that underlies our survival (i.e. the “triple bottom line” of people, planet and profit).

Sustainability is now shifting to more advanced concepts like net-zero and regenerative design, which seek to eliminate our impact on the environment or even turn that impact into a net positive.

LEED was launched in 1998 after a lengthy, consensus-based process overseen by USGBC and other organizations, and spearheaded by Robert K. Watson, a research scientist with the National Resources Defense Council (NRDC). Since the program’s launch, LEED has been through several different iterations, most notably LEED v2009, but all older versions sunset in 2022 or before and were replaced by LEED v4/4.1, which itself closes to new project registrations in 2026, after which LEED v5, launched in April 2025, will become the only version of LEED open for new registrations until it too is replaced by a new version in 2030.

LEED was and is by no means the only green rating system. In 1990, the Building Research Establishment (BRE), a British building science research organization, launched BREEAM, a wide-ranging, holistic sustainable rating system widely used today and one of LEED’s main competitors. Similarly, the Green Building Institute (GBI) has certified more than 750 million square feet of commercial and multifamily space under its Green Globes system since 2004. The International Living Future Institute’s Living Building Challenge is a more recent competitor, seeking to replicate LEED’s holistic structure in a more performance-based way. Other systems like the Sustainable Sites Initiative (SITES), the WELL building standard and Passive House focus on a narrower band of sustainable criteria like site design, indoor environment, or energy efficiency.

As sustainable design becomes more and more mainstream, the number and variety of systems providing sustainable certification is likely to grow. For now, LEED remains the most widely used and most recognizable way to certify that a building is sustainable.

Results

According to a recent USGBC impact report, there are 197,000 LEED certified projects in 186 countries totaling over 29 billion square feet worldwide – an area slightly greater than the country of Luxembourg. These buildings achieve on average 21.4% higher market sales per square foot over non-LEED buildings, 11% higher rents, more favorable and stable financing options, and reduce the waste of water, energy and materials by over 20%.

Many U.S. federal agencies, state and local governments require or reward LEED certification, and high-profile developer projects are often designed with LEED certification as a key stipulation.

However, LEED has received criticism since its early days for allowing the certification of projects that meet sustainability requirements on paper, but do not perform in practice. This vulnerability exists because LEED is a documents-based system which awards points based on design and construction documentation rather than post-construction verification of sustainable performance.

LEED is also an add-on expense. Project owners concerned about the sustainability of their buildings can stipulate prescriptive and performative requirements for energy efficiency, water efficiency, low carbon materials or indoor air quality without going through the hassle and expense of using LEED. But LEED remains a recognizable way of achieving sustainable goals, conferring the benefits of pre-defined sustainable requirements and instant public recognition into a streamlined process.

Impact Categories

Recent versions of LEED have been developed around “impact categories”, or major goals that shape the system’s requirements. LEED v4 had seven categories; LEED v5 reduces these to three:

• Decarbonization aims to reduce the operational, embodied, refrigerant and transportation-related greenhouse gas emissions caused by buildings.
• Quality of life aims to improve the health, well-being and resilience of building occupants and surrounding communities.
• Ecological conservation and restoration aims to limit the environmental degradation caused by building construction and operations, and to encourage building practices that contribute to ecosystem restoration.

LEED awards certification based on a project’s compliance with mandatory prerequisites and optional credits. Each credit and prerequisite in the new system is tied to one or several of the three impact areas explicitly, making it easier for project teams to explain how their design and operational choices tie in with sustainable objectives. In particular, the new system focuses on decarbonization and resilience to align the LEED system more closely with the Paris Climate Accord’s 2030 and 2050 targets.

System of Systems

LEED is not just one set of rules but rather a complex set of different systems for different contexts which links to other sustainable rating systems like WELL, PEER and SITES that specialize in a more limited field. Projects seeking LEED certification may choose from one of the following LEED standards:

• LEED for Building Design and Construction (LEED BD+C) certifies most project types that are new construction, major renovation or core and shell projects. This includes offices, residential, healthcare, data centers, schools, hospitality, retail and warehouses, among others.
• LEED for Interior Design and Construction (LEED ID+C) certifies interior fit-out projects like hotel lobbies, offices or retail stores in which project teams do not control the entire building’s design.
• LEED for Operations and Maintenance (LEED O+M) certifies the sustainable management and upkeep of existing buildings.
• LEED for Residential Design and Construction (LEED Homes) certifies new construction and major renovation projects in the multifamily, multifamily core and shell, duplex, townhouse and single-family residential categories. 
• LEED for Neighborhood Development (LEED ND) certifies planned or recently built neighborhood-scale real estate developments.
• LEED for Cities certifies entire existing cities, towns and other local government jurisdictions based on social, economic and environmental performance metrics.
• LEED for Communities certifies parts of cities such as real estate developments, corporate campuses or business improvement districts, including existing projects, new developments and redevelopments.

Overall, USGBC has positioned LEED to cover any type of project from a small house renovation to major urban redevelopment projects to entire cities.

Minimum Program Requirements

While LEED will certify almost anything human beings can build, the system does have limits. Each LEED system has Minimum Program Requirements that define what can and cannot be certified.

• Must be in a permanent location on existing land i.e. not a mobile home or built on a newly created artificial island.
• Must be of a minimum size: 1000 square feet (93 square meters) for LEED BD+C and LEED O+M, 250 square feet (22 square meters) for LEED ID+C.
• Must use reasonable LEED boundaries to define what is and is not included in the project. Usually this means the project’s property line, but in projects within a larger property it means land altered by construction and support facilities like parking lots or septic treatment facilities.

Certification Levels

LEED awards certification at four levels: Certified, Silver, Gold and Platinum. To achieve any level of certification, a project must comply with mandatory prerequisites which vary depending on the project’s rating system and building type – LEED BD+C projects must comply with 16 prerequisites.

To achieve each certification level, projects must also earn points by achieving the requirements of optional credits which total to a maximum of 110 points:

• LEED Certified needs 40 points
• LEED Silver needs 50 points
• LEED Gold needs 60 points
• LEED Platinum needs 80 points

Platinum sets a high bar at 80 out of 110 points, and requires projects aiming for LEED BD+C, ID+C or O+M to achieve certain specific credits which become mandatory prerequisites for Platinum projects.

Credit Categories

LEED BD+C, ID+C and O+M organize credits and prerequisites into eight functionally related groups called credit categories: Integrative Process (IP), Location and Transportation (LT), Sustainable Sites (SS), Water Efficiency (WE), Energy and Atmosphere (EA), Materials and Resources (MR), Indoor Environmental Quality (EQ), and Project Priorities (PR).

• Integrative Process, Planning and Assessments (IP) is a procedural category focused on pre-design analysis and the establishment of sustainable goals that support the project going forward. It aims to make sustainability part of the project’s DNA, rather than a superficial late addition.
• Location and Transportation (LT) focuses on the project’s surroundings, how it connects to those surroundings, and the impact of transportation on the environment.
• Sustainable Sites (SS) focuses on the conservation, restoration and optimal use of the project site itself through conserving habitat, minimizing disturbance, managing rainwater and making the site’s design resilient to disasters.
• Water Efficiency (WE) focuses on reducing potable water use through increased efficiency and alternative water sources.
• Energy and Atmosphere (EA) measures a project’s energy efficiency and greenhouse gas emissions and reflects a strong emphasis on decarbonization. EA is LEED’s largest credit category and has the largest number of mandatory prerequisites.
• Materials and Resources (MR) considers the impact of a project’s material choices on the environment and how to use natural resources more efficiently.
• Indoor Environmental Quality (EQ) emphasizes good indoor air quality, lighting, acoustics and thermal comfort for building occupants.
• Project Priorities and Innovation (PR) offers project teams a diverse range of options for extra credit beyond 100 points.

Process

The LEED process is a simple four-step process:

• Step 1: register the project.
• Step 2: prepare the application. Identify specific LEED credits to pursue and prepare documentation for each credit. Upload to LEED Online (v4) or Arc (v5).
• Step 3: submit the application. Each credit is either a design-phase credit (can be documented before project completion) or a construction-phase credit (can be documented after project completion). For a combined review, all credits are submitted at the end of the project. For a split review, credits are submitted in stages:
  • Preliminary design review for all or some design-phase credits. Credit documentation will be reviewed and feedback provided.
  • Final design review for all design-phase credits.
  • Preliminary construction review for all or some design-phase credits. Credit documentation will be reviewed and feedback provided.
  • Final construction review for all construction-phase credits.
• Step 4: receive certification.

Costs

Certification costs vary by project size and rating system, but will include:

• Registration (flat fee)
• Precertification (flat fee)
• Review (per square foot/meter with minimum)
• Appeals (per credit)
• Formal Inquiries (per inquiry)

Flat fees play more of a role for small projects and cost per square foot for large projects. For example, a 10,000 square foot project seeking LEED BD+C with a combined design and construction review and no expedited review, appeals or inquiries would cost $8,060; a 100,000 square foot project under the same conditions would cost $14,900.

This cost only covers what USGBC charges, not the costs of design and construction professionals working on the documentation necessary for LEED certification. This add-on to the regular design process may involve dozens or hundreds of additional workhours with a corresponding increase in the project’s soft costs, a cost project owners must balance against the benefits of LEED certification.

Conclusion

LEED is a widely recognized green building certification program that provides a framework for healthy, energy and resource-efficient and cost-saving sustainable buildings. Though comprehensive and intricate, aiming to encompass a broad spectrum of what constitutes a sustainable building and offering certification for projects ranging from small-scale renovations to entire urban developments, the LEED system can be quickly understood through these key points:

• LEED stands for Leadership in Energy and Environmental Design.
• LEED is a sustainable rating system developed by the US Green Building Council (USGBC) and administered by Green Business Certification Inc. (GBCI). 
• LEED was developed in the 1990s and launched in 1998.
• The most recent version of LEED is LEED v5, which was launched in 2025 and will be in use until about 2030.
• LEED has four levels of certification: Certified (40-49 points), Silver (50-59 points), Gold (60-69 points) and Platinum (80-110 points).
• LEED is based around three “impact areas”, Decarbonization, Quality of Life, Ecological Conservation and Restoration, that inform the point value of credits
• Minimum Program Requirements require most LEED projects to be permanently located on existing land, at least 1000 square feet, and contained within a reasonable LEED boundary.
• LEED projects must meet all mandatory prerequisites and enough optional credits to gain enough points for their desired certification level.
• LEED credits and prerequisites are organized into 8 credit categories:
  • Integrative Process, Planning and Assessments
  • Location and Transportation
  • Sustainable Sites
  • Water Efficiency
  • Energy and Atmosphere
  • Materials and Resources
  • Indoor Environmental Quality
  • Project Priorities
• LEED certification follows a simple, four-step process:
  • Register the project
  • Prepare the application
  • Submit the application, either with a combined or a split review
  • Receive certification
• LEED certification costs combine flat fees and per-area fees, plus workhours spent on documentation.

Whether you work in the design or construction industry or just have an interest in the built environment, understanding the LEED rating system is important because LEED is a critical player in a world where sustainability is increasingly the norm in building design, not the exception.

Resources

To learn more about LEED v5, check out USGBC’s page on LEED v5 and this blog’s ongoing series about the new system.

To understand LEED’s 25-year impact, read USGBC’s 2024 Impact Report

To understand the costs of LEED certification, read USGBC’s guide to LEED certification fees.