The starting point for choosing a green building certification is the outcome your project needs to achieve. Resource efficiency, occupant health, a broad environmental assessment and Türkiye's national certification requirements may call for different preparation. Whether a building is new, undergoing major renovation or already in use also affects the appropriate assessment route.
This comparison provides an initial framework for building projects. Selection should consider the building type, project stage, ownership and occupancy boundaries, and the applicable certification pathway together.
What does each system focus on?
| System | Main focus | Project scope and suitability |
|---|---|---|
| LEED | Takes a broad approach to energy, water, materials, indoor environments and other sustainability topics. | Covers uses such as offices, hotels, schools and data centres. Separate pathways address new buildings and major renovations, interior projects, and buildings in operation. It suits teams seeking a broad sustainability framework. |
| EDGE | Focuses on resource efficiency through energy, water and building materials. | Eligibility for new or existing buildings is checked for uses such as offices, hotels, education and healthcare. It addresses teams seeking to connect resource efficiency with design decisions. |
| WELL | Addresses occupant health and well-being through spaces, operational practices and organisational policies. | The scope is established for building and interior uses such as offices and hotels. WELL Core is a distinct route for owners addressing the base building and common areas of predominantly tenant-occupied buildings. It addresses teams prioritising occupant experience and healthy indoor environments. |
| BREEAM | Assesses a building's environmental and sustainability performance within a broad framework. | An appropriate standard is selected for uses such as offices, industrial buildings, retail and housing. New construction, refurbishment and fit-out, and buildings in use are addressed separately. It suits teams seeking an environmental assessment for the relevant building life stage. |
| YeS-Int | Türkiye's national green certification system; its building assessment covers topics including design, materials, indoor environments, energy, water and waste. | The relevant guide applies to new and existing buildings in uses such as housing, offices, education, hotels, healthcare and shopping centres. It is relevant to teams pursuing national certification in Türkiye or assessing duties under the applicable legislation. |
Official scope references: USGBC — LEED rating system selection, IFC — EDGE certification, IWBI — WELL, IWBI — WELL Core, BRE — BREEAM standards, Ministry — Green certificate guide for public buildings, in Turkish, Official Gazette — Green Certificate Regulation annexes, 28 Oct 2026, in Turkish.
What are the certification levels called?
| System or assessment pathway | Official level names |
|---|---|
| LEED | Certified, Silver, Gold, Platinum |
| EDGE | EDGE Certified, EDGE Advanced, EDGE Zero Carbon |
| WELL v2 | Bronze, Silver, Gold, Platinum |
| BREEAM New Construction | Pass, Good, Very Good, Excellent, Outstanding |
| BREEAM In-Use | Acceptable, Pass, Good, Very Good, Excellent, Outstanding |
| YeS-Int building assessment | Geçer, İyi, Çok İyi, Ulusal Üstünlük |
Similar level names do not mean equivalent outcomes across systems. EDGE Zero Carbon, for example, has separate requirements addressing emissions from operational energy; it does not mean that all carbon impacts across a building's life cycle have been eliminated. BREEAM's rating names for new construction and buildings in use should also be read separately. The YeS-Int names above retain their official Turkish wording.
Official level references: USGBC — LEED, IFC — EDGE frequently asked questions, IWBI — WELL Certification, BRE — BREEAM New Construction, BRE — How BREEAM works (rating levels), Ministry — Green certificate guide for public buildings, in Turkish.
How does the application process work?
Preparation starts by identifying the appropriate system and project boundaries. Relevant design decisions, installed measures or operational data are then documented. Review, auditing and certification decisions follow the rules of the selected system.
- LEED: The team selects an appropriate rating system and registers the project. Relevant design, construction or operational evidence is prepared for GBCI review.
- EDGE: Project information and efficiency measures are assessed through the EDGE App. Design and completed-building stages are audited according to the application route; existing buildings may proceed directly to final certification.
- WELL: The scope is established alongside design and operational practices. Documentation review and the applicable performance verification form part of certification.
- BREEAM: Evidence is prepared and assessed with a licensed assessor under the relevant standard. For new construction, a design-stage assessment is distinct from the final post-construction assessment.
- YeS-Int: The scope and evidence are prepared using the relevant guide. The application is prepared by a Ministry-authorised Green Certificate Expert (YESU) and submitted via YeS-Int to the assessment body, which carries out the assessment and issues the certificate.
Process references: USGBC — LEED certification, IFC — EDGE applications and audits, IWBI — WELL project and performance testing roles, BRE — How BREEAM works, Ministry — Green certificate guide for public buildings, in Turkish.
How can you narrow down the choice for your project?
Start by defining the building's intended use, project stage and desired outcomes. Then identify which drawings, calculations and operational records the team already holds. This connects the certification objective to design and implementation decisions and makes additional analysis needs visible.
Explore AECO's LEED, EDGE, WELL and YeS-Int consulting services. Our building energy modeling and daylight analysis pages also explain how technical analysis can support energy and indoor environment decisions. Share your building's use, project stage and priorities with us to define an appropriate consulting scope together.