Home | Overview | Background | Assessment Method | Assessment Tool | Download | Statistics | Link


Measures to Promote Sustainability

Buildings, which consume and discard resources and energy in enormous quantities, are one of architectural category which we must act urgently to develop and promote techniques and policies able to assist the drive towards sustainability. There has been a growing movement towards sustainable construction since the second half of the 1980s, leading to the development of various methods for evaluating the environmental performance of buildings. Methods developed overseas include BREEAM (Building Research Establishment Environmental Assessment Method) in the UK, LEEDTM (Leadership in Energy and Environment Design) in the USA, and SB Tool (Sustainable Building Tool) as an international project. These methods have attracted interest around the world. This kind of assessment, with the publication of the results, is one of the best methods now available to provide an incentive for clients, owners, designers and users to develop and promote highly sustainable construction practices.

CASBEE was developed according to the following policies:

1) The system should be structured to award high assessments to superior buildings, thereby enhancing incentives to designers and others.
2) The assessment system should be as simple as possible.
3) The system should be applicable to buildings in a wide range of building types.
4) The system should take into consideration issues and problems peculiar to Japan and Asia.

Framework of CASBEE: CASBEE Family

Building Lifecycle and Four Assessment Tools

As shown in figure1, CASBEE was developed in the suite of architectural design process, starting from the pre-design stage and continuing through design and post design stages.


Figure 1. The cyclical process of building design


Corresponding to the building lifecycle, CASBEE is composed of four assessment tools, CASBEE for Pre-design, CASBEE for New Construction, CASBEE for Existing Building and CASBEE for Renovation, and to serve at each stage of the design process (figure 2). CASBEE Family is the collective name for these four basic tools and the tools for specific purposes. Each tool is intended for the specific purpose and target users, and is designed to accommodate a wide range of building types (offices, schools, apartments, etc.).

Figure 2. Building Lifecycle and Four Assessment Tools
(click the above image for enlarging.)

Four Basic Tools

CASBEE for Pre-design (underdevelopment)
This tool aims to assist the owner, planner and others involved at the planning (pre-design) stage of the project. It has two main roles:
1) To assist in grasping issues such as the basic environmental impact of the project and selecting a suitable site.
2) To evaluate the environmental performance of the project at the Pre-design stage.

CASBEE for New Construction
This is a self-assessment check system that allows architects and engineers to raise the BEE value of the building under consideration during its design process. It makes assessments based on the design specification and the anticipated performance. It can also serve as a labeling tool when the building is subjected to expert third-party assessment.

CASBEE for Existing Building
This assessment tool targets existing building stock, based on operation records for at least one year after completion. It was developed to be applicable to asset assessment as well.

CASBEE for Renovation
There is growing demand for building stock renovation, especially in Japanese market. In the same way as gCASBEE for Existing Building,h this tool targets existing buildings. It can be used to generate proposals for building operation monitoring, commissioning and upgrade design with a view to ESCO (Energy Service Company) projects, which will be increasingly important in future, and for building stock renovation.

CASBEE for Specific Purposes

We have also developed the various versions of CASBEE according to the specific purposes.

(1) For Detached houses
The CASBEE basic tools are applicable for apartment complexes, but not detached houses.
CASBEE for Detached Houses was developed for an assessment of detached houses.

(2) For Temporary Construction
The tool "CASBEE for Temporary Construction," was developed as an extension tool of CASBEE for New Construction. It can be applied for assessment of temporary buildings for short-term use like exhisibition hall and olimpic facilities.

(3) Brief versions
Assessment by CASBEE for New Construction may take 3-7 days in case of including the time to prepare evidence documents and calculate the related items. The brief versions were developed to meet the growing needs for tools to handle objectives shown below.

1) The need for setting goals of the built environment efficiency in the early stage of building project (as a tool for consensus forming between owners, designers and builders, etc.).
2) The need for setting management targets of environmental performance of existing buildings (like a management tool under ISO14001 etc.).
3) The need for establishing the report system by local governments (like Nagoya city, Osaka city and Yokohama city etc.).

There are 3 brief versions of the basic tools, CASBEE-NC brief version, CASBEE-EB brief version and CASBEE-RN brief version. They are simplified and can be completed the assessment in around couple of hours (excluding time for the preparation of an Energy Saving Plan). In addition, the brief version of CASBEE for Urban Development have also been developed.

(4) Local goverment versions
As noted above, CASBEE is used by some local governments in Japan. The local governments tailor it to local conditions, such as climate and prioritized policies. Changes are generally made by modifying the weighting coefficients. Report of the assessment result to the local goverment is mandatory in the same way as the Energy Saving Plan and the building approval application. As of December 2011, 24 local governments have been introduced the reporting system as their environmental policies. The details are shown in statistics page.

(5) For Heat Island Effect
The heat island effect is becoming a critical issue in major urban areas, such as Tokyo and Osaka. CASBEE-HI (Heat Island) was developed to evaluate efforts in buildings to alleviate the heat island effect. The role is to make a more detailed and quantitative assessment of the heat island-related items of the basic tools.

(6) For Urban Development
The basic CASBEE tools can evaluate individual buildings, not building groups. Many recent city-center redevelopment projects have been planned for integration with their surrounding districts and delivering positive effects for the environment, like promoting the use of area energy networks. Even if each individual building has a different owner, taking the common environmental measures on buildings within a district can raise environment quality and performance throughout the area. CASBEE for Urban Development was developed to make broader assessments, adopting holistic approach delivered through the urban area

(7) For Cities
Recenty, people became highly aware of the importance of actions at the city level for the creation of low carbon societies. Countries and cities around the world have been implementing a variety of programs and polices for that purpose. CASBEE for Cities is a system for complehensively evaluating the environmental performance of cities, using a triple bottom line approach of "environment", "society" and "economy". It can objectively assess the effectiveness of the city's policies and environmental measures.

Table 1 Expansion of CASBEE for specific purposes (as of Dec.2011)

For Detached Houses
CASBEE for Detached Houses
(for New Construction, for Existing Building)
For Temporary Construction CASBEE for Temporary Construction
Brief versions
CASBEE for New Construction (Brief Version), for Existing
Buildings (Brief version), for Renovation (Brief version)
CASBEE for Urban Development (Brief version)
Local government versions CASBEE-Nagoya, CASBEE-Osaka, CASBEE-Yokohama etc.
For Heat Island effect
CASBEE for Heat Island
For Urban Development
CASBEE for Urban Development
For Cities
CASBEE for Cities


Research and Depelopment Organization

Research and development of CASBEE is a joint industrial/government/academic project established under the support of the Japanese ministiry of Land, Insrastructure, Transport and Tourism. The CASBEE Research Committee and its affiliated sub-committees established at Japan Sustainable Building Consortium provide overall project operation as shown in the chart below.

Copyright (C) Japan GreenBuild Council (JaGBC) / Japan Sustainable Building Consortium (JSBC),
All Rights Reserved.