A reading route in three steps
- Learn the concepts. Start with the four questions below for an introduction to green buildings and certification systems.
- Follow the process. Read about the LEED certification process and its scoring structure.
- Connect it to projects. Explore service scopes through our reference projects.
Core concepts
What is a green building?
A green building is a structure that saves energy and water, is built using environmentally responsible materials, and uses natural resources efficiently. These buildings aim to improve people's quality of life while minimizing negative effects on the environment.
What is a green building certificate?
A green building certificate is a document showing that a structure has been evaluated against criteria such as energy efficiency, water conservation, environmentally friendly materials and sustainability, and meets defined standards. These certificates are issued by independent organizations and encourage environmentally responsible building practices.
Why are there multiple certificates?
The main reasons there are several green building certificates are:
1. Geographic Differences: Different countries and regions have different priorities depending on climate, natural resources and construction traditions. Special certificates suited to local conditions have therefore been developed.
2. Different Methods and Criteria: Green building certificates differ in their assessment methods and criteria. This offers the construction industry and building owners a variety of options, letting them choose the certificate that suits them best.
3. Sectoral Needs: Special certificates have been developed for different building types and sectors (residential, commercial, industrial, etc.). These provide a more focused approach to sustainability goals within each sector.
4. Competition and Innovation: Multiple certification systems encourage competition and innovation, driving the continuous improvement of green building practices, pushing the industry toward higher standards.
For example, widely used green building certificates around the world include LEED, EDGE, BREEAM and WELL.
Which certificate is most preferred?
The most preferred green building certificate worldwide is LEED (Leadership in Energy and Environmental Design). Developed by the U.S. Green Building Council (USGBC), LEED is a comprehensive system that evaluates buildings against criteria such as energy efficiency, water conservation, indoor air quality, material selection and sustainable site use.
The LEED certificate can be used for residential, commercial and industrial buildings, with versions tailored to different building types and projects. LEED certified buildings are accepted worldwide as a standard for environmentally friendly and sustainable building practices.
Get to know the certification systems
Explore LEED, WELL, EDGE and other systems in our green building certification guide. Consider the building type, intended use, project stage and assessment scope when choosing a system, alongside its recognition.
Certification systems and professional credentials
Certification systems assess projects against defined criteria. Professional credentials describe an individual’s knowledge or role within a programme. A personal credential does not certify a building.
Four certification systems
- LEED
A certification system developed by USGBC to assess the environmental performance of buildings.
- EDGE
A green building certification system developed by IFC, focused on resource efficiency in energy, water and building materials.
- WELL
A system that assesses how buildings support human health and well-being through factors such as air, water, light and comfort.
- YeS-Int (YeS-TR)
Türkiye’s national green certification system, assessing buildings and settlements against environmental, social and economic criteria.
Eight professional credentials
- LEED AP BD+C
A LEED professional credential for building design and construction. BD+C stands for Building Design and Construction.
Official programme information ↗ Search the credential directory ↗
- LEED AP O+M
A LEED professional credential for the operation and maintenance of existing buildings. O+M stands for Operations and Maintenance.
Official programme information ↗ Search the credential directory ↗
- WELL AP
A professional credential covering the WELL Building Standard’s requirements for human health and well-being.
Official programme information ↗ Search the credential directory ↗
- EDGE Expert
A credential for specialists who guide project teams through certification preparation using EDGE criteria and its software.
Official programme information ↗ Search the credential directory ↗
- EDGE Auditor
A credential for auditors who review an EDGE submission and its evidence for compliance. The relevant certification provider makes the certification decision.
Official programme information ↗ Search the credential directory ↗
- ENV SP
Envision Sustainability Professional: a professional credential for using the Envision framework to assess sustainability in infrastructure projects.
- Certified Passive House Designer
A personal credential for designing buildings to the Passive House standard’s principles of low energy demand and indoor comfort.
Official programme information ↗ Search the credential directory ↗
- Yeşil Sertifika Uzmanı (YESU)
A green certification specialist qualification for preparing building or settlement documentation and supporting applications within Türkiye’s YeS-Int system.
Directory links open the issuing organisations’ search pages. Search by name to review a person’s published record.
This content introduces the fundamentals. For assignments, research or exam preparation, check technical requirements against the relevant system's current official documentation.