Green Building Certifications 2026: A Guide to the New Criteria

In 2026, green building certifications are no longer focused solely on energy and water efficiency. New assessment systems take a more comprehensive approach, considering carbon emissions, occupant health, climate resilience, material selection and the building’s actual operational performance. So, which criteria do LEED v5, BREEAM V7, WELL v2 and B.E.S.T. prioritise?

Green Building Certification Priorities for 2026

Assessing a building’s sustainability based solely on its operational energy consumption is no longer sufficient. The entire life cycle must now be considered, from the production of construction materials to the operation of the completed building.

The key green building criteria for 2026 include:

• Reducing operational and embodied carbon
• Using renewable energy
• Building resilience to climate-related risks
• Selecting circular and low-carbon materials
• Measuring water and energy consumption
• Improving indoor air quality
• Supporting occupant health and comfort
• Biodiversity protection
• Transparently reporting performance data

This shift demonstrates that certification targets should not be treated as a checklist added to the project at a later stage. Sustainability decisions need to be incorporated into the design, engineering, procurement, construction and operational processes from the very beginning.

To explore how ESG criteria influence building design in greater detail, read our article, Sustainable Construction Projects: How Can Buildings Be Designed in Line with ESG Criteria?

What Has Changed with LEED v5?

Published in 2025, LEED v5 highlights three key impact areas for projects in 2026:

1. Decarbonisation
2. Quality of life
3. Ecological conservation and restoration

Under decarbonisation, the system assesses not only operational emissions generated through the building’s use but also the embodied carbon of construction materials, refrigerants and transport-related emissions.

Quality-of-life criteria cover areas such as indoor air quality, accessibility, occupant safety and inclusive design. Ecological conservation and restoration focus on protecting natural habitats, using native plants, managing stormwater and enhancing the ecological value of the site.

Projects targeting LEED v5 should therefore begin preparing energy models, life cycle assessments and material data during the early stages of design.

What Does BREEAM V7 Focus On?

BREEAM V7 aims to assess a building’s environmental impact throughout its entire life cycle. This approach considers the impacts associated with the production, transportation, installation and maintenance of materials, as well as their end-of-life treatment.

The new criteria place particular emphasis on:

• Life cycle and embodied carbon calculations
• Low-carbon materials with verified environmental data
• Regular monitoring of energy consumption
• Resilience to climate change
• Circular economy principles and waste management
• Biodiversity protection

BREEAM V7 also aims to reduce the gap between performance calculated during the design stage and the building’s actual operational performance. Accurate energy modelling, systems commissioning, metering infrastructure and post-occupancy performance monitoring are therefore becoming increasingly important.

To discover how energy and building performance can be managed through digital data, read our article, Smart Facility Management with Digital Twins in 5 Steps.

How Does WELL v2 Assess Human Health?

While LEED and BREEAM address environmental performance within a broad framework, WELL v2 focuses directly on occupant health and wellbeing.

The current WELL v2 framework consists of ten core concepts:

• Air
• Water
• Nourishment
• Light
• Movement
• Thermal comfort
• Sound
• Materials
• Mind
• Community

In office projects, measuring indoor air quality, maximising access to daylight, providing acoustic comfort and selecting low-emission materials are particularly important. Spaces that encourage movement, areas designed for rest and inclusive design decisions also contribute to a better occupant experience.

Within the WELL system, it is not enough for health-related targets to appear only in project documentation. Criteria such as air, water, light and thermal comfort must be verified through the required measurements and performance tests.

The Role of B.E.S.T. Certification in Türkiye

B.E.S.T. is a local green building certification system developed by the Turkish Green Building Council to reflect the specific conditions of Türkiye.

The system provides a holistic assessment across different areas, including land use, water, energy, health and comfort, material use, operations and maintenance. Its consideration of Türkiye’s climate zones, construction industry and local implementation conditions is one of B.E.S.T.’s key advantages.

Particularly for local residential and commercial developments, it can provide a sustainability roadmap that serves as either an alternative or a complement to international certification systems.

Which Green Building Certification Should You Choose?

There is no single certification system suitable for every project. The right choice should be determined according to the project’s location, intended use, investment goals and occupant profile.

• LEED v5: For projects seeking international recognition and ambitious carbon targets
• BREEAM V7: For projects focused on life cycle performance, resilience and biodiversity
• WELL v2: For projects prioritising occupant health and workplace experience
• B.E.S.T.: For projects seeking a system aligned with Türkiye’s local conditions

Some projects may pursue more than one certification. For example, LEED or BREEAM can be used to assess environmental performance, while WELL can support occupant health and wellbeing. Before making this decision, however, overlapping criteria, documentation requirements and the available budget should be carefully analysed.

How Should You Prepare for the Certification Process?

A successful certification process begins with defining the project’s objectives and selecting the most appropriate certification system. The existing design should then be assessed against the relevant criteria to identify mandatory requirements and potential areas of risk.

Bringing architects, engineers, sustainability consultants, contractors and facility management teams together at an early stage helps the process move forward in a more coordinated manner. Energy models, material documentation, water calculations and waste records should also be prepared and updated regularly as the project progresses.

To learn more about Diem’s integrated approach to design, engineering, project management and construction, explore our services.

From Certification to Measurable Performance

In 2026, green building certifications are moving beyond design targets to focus on the impact a building creates throughout its entire life cycle. LEED v5 and BREEAM V7 strengthen carbon and resilience criteria, while WELL v2 prioritises occupant health and B.E.S.T. focuses on conditions specific to Türkiye.

To plan your project’s sustainability targets from the earliest design stages and develop a roadmap tailored to your organisation, explore Diem’s ESG services.