WELL vs. LEED vs. BREEAM: The Complete 2026 Comparison Guide

WELL, LEED and BREEAM are the three most widely used building certifications in commercial real estate, and they measure different things. LEED and BREEAM certify environmental sustainability. WELL certifies human health and well-being. Most high-performing buildings pursue one of LEED or BREEAM for sustainability, and add WELL when occupant health is a priority.

This guide explains what each certification covers, how the rating levels work, what they cost, where each one dominates, and how to decide which to pursue. It reflects the two biggest recent changes to the frameworks: LEED v5, released in April 2025, and BREEAM Version 7, which became the mandatory standard for new registrations in early 2026.

The difference at a glance

The short version: LEED and BREEAM certify how green the building is. WELL certifies how healthy it is for the people inside. Most prime assets pick one of LEED or BREEAM, then add WELL on top.

What is LEED certification?

LEED (Leadership in Energy and Environmental Design) is a green building rating system developed by the U.S. Green Building Council. It is the most widely used sustainability certification in the world, active in 185 countries with more than 200,000 certified projects.

LEED evaluates a building across categories including energy and atmosphere, water efficiency, sustainable sites, materials and resources, indoor environmental quality, and innovation. Projects earn points, and the point total determines the certification level.

LEED certification levels

What changed in LEED v5 (April 2025): LEED v5 reorganizes the system around three impact areas: decarbonization (roughly half of all credits), quality of life (a quarter), and ecological conservation and restoration (a quarter). Every project must now complete three assessments as prerequisites: a carbon assessment, a climate resilience assessment, and a human impact assessment. Platinum has become harder to reach, adding requirements for full electrification, 100% renewable energy, and a minimum 20% reduction in embodied carbon against a baseline. LEED v5 became available in 2025, with full applicability required from June 2027, so both v4 and v5 projects are in the market today.

What is BREEAM certification?

BREEAM (Building Research Establishment Environmental Assessment Method) is the world's longest-established building sustainability method, developed by BRE in the UK in 1990. It assesses environmental, social and economic sustainability, and it dominates the European market with an estimated 80% share.

BREEAM scores buildings across ten categories: energy, water, materials, ecology (land use), health and well-being, transport, waste, pollution, management, and innovation. The final score is expressed as a percentage, which maps to a rating.

BREEAM rating levels

What changed in BREEAM Version 7 (2025 to 2026): Version 7 shifts BREEAM away from theoretical design assumptions toward measurable, in-use outcomes. The headline change is at the top of the scale: an Outstanding rating now prohibits on-site fossil fuel combustion entirely, with no gas boilers, pushing projects toward heat pumps, geothermal and on-site renewable generation. BREEAM Version 6 was retired for new registrations in early 2026, making V7 the standard for new projects. BREEAM also runs a separate scheme, BREEAM In-Use, for assessing existing operational buildings, which is where much of the European portfolio activity sits.

What is WELL certification?

WELL is a certification developed by the International WELL Building Institute that measures how a building supports the health and well-being of the people who use it. Where LEED and BREEAM look outward at environmental impact, WELL looks inward at the occupant. It has grown roughly twelve times since 2020 and remains the only major standard built specifically around human health.

The current standard, WELL v2, is organized into ten concepts: air, water, nourishment, light, movement, thermal comfort, sound, materials, mind, and community. It contains 108 features, split into 24 preconditions (mandatory for any level) and 84 optimizations (optional points toward higher levels).

WELL certification levels

Projects can earn up to 100 points across the ten concepts, plus up to 10 additional points for innovation. A distinctive feature of WELL is performance verification: an agent conducts on-site testing of things like air and water quality, so certification reflects measured performance rather than design intent alone.

WELL vs. LEED vs. BREEAM: side-by-side comparison

Here is how the three compare on the aspects that usually decide which one to pursue.

The pattern to notice: LEED and BREEAM answer how green the building is, from different angles. WELL answers a different question entirely: is it good for the people inside? That is why they stack rather than compete.

How much does each certification cost?

Costs vary widely with building size, complexity and target level. As a rule of thumb, USGBC estimates that certifying a building costs roughly 2% of total construction cost. The figures below are registration and assessment fees only, and exclude the design and construction upgrades needed to actually earn the rating, which are usually the larger expense.

Rule of thumb: the fees are the small part. The real cost is the building work needed to earn the rating, and that is where accurate baseline data pays for itself.

Where is each certification used?

Geography is often the deciding factor. LEED is the most global standard and is especially strong in the United States, Asia-Pacific and the Middle East. BREEAM is the default across Europe, holding roughly 80% of the European market and near-total dominance in the UK. WELL is used worldwide but concentrates in offices and workplaces where occupant health has a direct link to productivity and talent retention.

For a European commercial portfolio, BREEAM, and BREEAM In-Use for existing buildings, is usually the practical baseline. For a portfolio with US or Asian assets, or one reporting to international investors who recognize LEED, LEED often makes more sense. WELL is typically added on top of either, rather than chosen instead of them.

Can a building have LEED, BREEAM and WELL at the same time?

Yes. These certifications are complementary, not mutually exclusive, and pursuing more than one is common in high-end commercial real estate. Because LEED and BREEAM both cover environmental sustainability, teams usually pick one of the two rather than both. WELL is the natural addition, since it covers a different dimension, health, with relatively little overlap.

The frameworks share enough underlying data, particularly around energy, water, air quality and materials, that documentation gathered for one can support another. IWBI and GBCI have also published crosswalks to reduce duplicated effort between WELL and LEED. A building certified under both an environmental standard and WELL signals to tenants and investors that it performs on sustainability and on the experience of the people inside it.

Which certification should you choose?

Use this as a starting decision guide.

The common thread: all three now run on measured data

The clearest trend across the latest versions of all three frameworks is the shift from design-stage promises to verified, in-use performance. LEED v5 puts operational and embodied carbon at the center and requires carbon assessment. BREEAM Version 7 is built around measurable outcomes rather than theoretical design. WELL already requires on-site testing of air, water and other conditions.

That shift has a practical consequence: certification and recertification increasingly depend on accurate, continuous utility and environmental data from the building itself. Estimated or manually collected readings are no longer enough. Energy, water, gas and heat consumption need to be measured reliably, at the meter and submeter level, and kept audit-ready over time.

What this means in practice: design-stage credits are giving way to measured, in-use performance. Certification now depends on the quality of your metering data.

This is where consumption monitoring becomes part of the certification workflow rather than a separate exercise. Rhino connects to the meters already in a building, across electricity, gas, water and heat, and automates the collection of accurate consumption data across a whole portfolio. That gives sustainability and property teams the verified numbers that LEED v5, BREEAM v7 and WELL performance reviews now expect, without the quarter-end scramble to chase readings across spreadsheets.

See how Rhino keeps portfolio utility data audit-ready for ESG reporting

Frequently asked questions

What is the main difference between WELL, LEED and BREEAM?

LEED and BREEAM certify a building's environmental sustainability, while WELL certifies how the building affects the health and well-being of its occupants. LEED is the most global standard, BREEAM leads in Europe, and WELL is the only major standard focused on human health.

Is BREEAM or LEED better?

Neither is objectively better; the right choice depends on location and audience. BREEAM dominates Europe and the UK and takes a broader lifecycle view including social and economic factors. LEED is more global, with strong recognition in the US, Asia and the Middle East. Many portfolios choose based on where their assets are and which standard their investors recognize.

Can a building be both LEED and WELL certified?

Yes. Because LEED covers environmental sustainability and WELL covers occupant health, the two are complementary and are frequently pursued together. Shared documentation and published crosswalks reduce the extra effort of certifying under both.

What are the certification levels for each?

LEED has Certified, Silver, Gold and Platinum. BREEAM has Pass, Good, Very Good, Excellent and Outstanding. WELL has Bronze, Silver, Gold and Platinum.

What is LEED v5?

LEED v5 is the latest version of LEED, released in April 2025, with full applicability required from June 2027. It reorganizes the system around decarbonization, quality of life, and ecological conservation, and adds mandatory carbon, climate resilience and human impact assessments.

What changed in BREEAM Version 7?

BREEAM Version 7, which became the mandatory standard for new registrations in early 2026, shifts the focus from theoretical design to measurable outcomes. Its Outstanding rating now prohibits on-site fossil fuel combustion, effectively ruling out gas boilers at the top level.

How much does green building certification cost?

Registration and assessment fees typically run from a few thousand to around €20,000 depending on building size and complexity. USGBC estimates the total cost of certifying a building at roughly 2% of construction cost, most of which goes to the building improvements themselves rather than the fees.

Do these certifications require metered energy data?

Increasingly, yes. The latest versions of all three emphasize verified, in-use performance, which relies on accurate energy, water, gas and heat data measured at the meter and submeter level, kept consistent and audit-ready over time.