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CASBEE® is a registered trademark of the Institute for Built Environment and Carbon Neutra for SDGs (IBECs) , a general incorporated foundation.
1. What is CASBEE®
CASBEE®（Comprehensive Assessment System for Built Environment Efficiency） is Japan’s premier green building certification system, established in 2002. It provides a comprehensive framework for evaluating and rating the environmental performance of buildings. Beyond simple energy efficiency and the use of eco friendly materials (Environmental Load Reduction), the system conducts a holistic assessment that includes Environmental Quality—such as indoor comfort, biodiversity, and harmony with the surrounding landscape.
2. Eligible Projects
To ensure the highest standards of integrity and transparency, projects can obtain Third-Party Certification through the official CASBEE® certification body. The system is categorized into five specialized tools based on the project type:
- CASBEE® for Building Design: (New Construction / Existing Building /Renovation)
- CASBEE® for Detached Houses
- CASBEE®for Real Estate
- CASBEE®for Wellness Office
- CASBEE®for Urban Development
3. Assessment Items
CASBEE® evaluates buildings based on four primary environmental categories.
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Energy Efficiency
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Resource Efficiency
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Outdoor Environment
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Indoor Environment
4. Process
Applications for CASBEE® certification are processed through authorized certification bodies accredited by the Institute for Built Environment and Reduced CO2 Emissions (IBECs). The evaluation report, prepared by a certified CASBEE® Accredited Professional, undergoes a rigorous review by the certification body. Upon successful verification of the assessment, an official certificate is issued to the project.
5. CASBEE® Accredited Professional
Under the CASBEE® certification system, any assessment performed using the official evaluation software must be conducted by a CASBEE® Accredited Professional. Woonerf houses a team of several certified CASBEE® Professionals. We provide expert advisory and end-to-end support to help you achieve your target rating and successfully secure CASBEE® certification for your projects.
6. Certification levels
The assessment results are based on Built Environment Efficiency (BEE), a value calculated from the balance between Environmental Quality (Q) and Environmental Load (L). Based on this score, projects are classified into five distinct ranks:
| Rank | Rank Criteria | Definition / Criteria | Rating |
|---|---|---|---|
| S | Excellent | BEE ≥ 3.0 and Q ≥ 50 | ★★★★★ |
| A | Very Good | 1.5 ≤ BEE < 3.0 | ★★★★ |
| B+ | Good | 1.0 ≤ BEE < 1.5 | ★★★ |
| B- | Fairly Poor | 0.5 ≤ BEE < 1.0 | ★ |
| C | Poor | BEE < 0.5 | ★ |
7. Fees
To obtain CASBEE® certification, applicants are responsible for both the consulting fees and the official review fees charged by the authorized certification body. Total project costs vary depending on several factors, including the building’s total floor area, intended use, and the complexity of the assessment.