Nils LARSSON: The SBTool

Nils LARSSON is Executive Director of the International Initiative for Sustainable Built Environment ( iiSBE). He's also coordinating the International SD-MED Forum.

Nils LARSSON est le Directeur Exécutif de iiSBE (International Initiative for Sustainable Built Environment ). Il est aussi coordinateur du Forum International SD-MED.

SBTool is the software implementation of the Green Building Challenge (GBC) assessment method that has been under development since 1996 by a group of more than a dozen teams.  The GBC process was launched by Natural Resources Canada, but responsibility was handed over to the International Initiative for a Sustainable Built Environment (iiSBE) in 2002.  The generic method and software is calibrated by national teams to suit their local conditions, and is then tested on case study buildings.  Results are displayed at international SB conferences, the most recent of which was the Tokyo SB05 conference in late September 2005.

The GBC assessment method is one of several systems that have been implemented around the world.  The best-known systems are undoubtedly BREEAM, a system primarily used in the UK, and LEED, a system mainly confined to North America.  BREEAM was the first system of this type and has been very influential since its development in the early 1990's.  LEED is now growing at a very rapid rate and has undoubtedly been responsible for a major shift in industry attitudes in North America.

The GBC method and SBTool represents another approach.  SBTool is a generic framework, and should perhaps be seen as a toolkit that allows local organizations to develop one or more rating systems that suit the region.  The method places emphasis on the ability to have the system reflect the relative importance of performance issues in a particular region, and also to contain regionally relevant benchmarks. By replacing the generic benchmarks provided in the system with their own, regional authorities can ensure that the system will be relevant to their unique local conditions.

IiSBE is primarily involved in R&D and in helping local teams to come to grips with performance assessment, but we are also prepared to undertake large projects on a commercial basis.

Features of SBTool

n SBTool is a generic framework for rating the sustainable performance of buildings and projects.  It may also be thought of as a toolkit that assists local organizations to develop rating systems.

n The system covers a wide range of sustainable building issues, not just green building concerns, but the scope of the system can be modified to be as narrow or as broad as desired, ranging from 145 criteria to half a dozen;
n The system allows third parties to establish parameter weights that reflect the varying importance of issues in the region, and to establish relevant benchmarks by occupancy type, in local languages.  Thus, many rating systems can be developed in different regions that look quite different, but share a common methodology and set of terms.  The main advantage, however, is that an SBTool version developed with local knowledge is likely to be much more relevant to local needs and values than other systems;
n The system permits assessments to be carried out at four distinct stages of the life-cycle and provides default benchmarks suited to each phase;
n Local organizations can select up to three building types out of a total of 18, and apply them separately or in a mixed-use project;
n SBTool takes into account region-specific and site-specific context factors, and these are used to switch off or reduce certain weights, as well as providing background information for all parties.
n The system handles large projects or single buildings, residential or commercial, new and existing construction, or a mix of the two;
n The system can provide approximations of annualized embodied energy for structural and building envelope components.
n Designers can specify performance targets and can score self-assessed performance;
n Assessors can accept self-assessed performance scores submitted by designers, or can modify them.

SBTool is designed to allow assessments to be carried out at various phases of the life cycle of a project.  Parameters included within the system cover sustainable building issues within the three major areas of environment, social and economic sectors.

A distinguishing feature of SBTool is that it is designed as a generic framework, and requires a third party to adjust it to suit the unique conditions applicable to certain building types in various regions.  This means that an assessment carried out using the system has little validity unless such a calibration feature is first carried out.  Third party organizations are expected to adjust default weights, benchmarks and emission values throughout the system. 

Default weights have been established by identifying strong, moderate or weak links between SBTool Criteria (the lowest level parameter type) and a small group of broad sustainability issues.  These links are then weighted according to the apparent relative importance of the sustainability issue.  All of these numbers are adjustable by authorized third-party organizations.