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About GBTool and GBC2005 downloadable files
GBTool 2005 ( GBTool-A, GBTool-B ) implemented on an Excel spreadsheet is available for downloading for academic or research purposes.

GBTool 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 countries. The GBC process was begun with Natural Resources Canada, but responsibility was handed over to the International Initiative for a Sustainable Built Environment (iiSBE) in 2002. The generic software is modified by national teams to suit their local conditions, and is then tested on case study buildings. Currently, some 15 countries are involved in preparing assessments that will be exhibited at the global Tokyo SB05 conference in late September 2005.

Users of this software should be aware of the following limitations and conditions:

The system is a framework, not a simulation model. Users are expected to use other software tools to simulate energy performance, estimate embodied energy and emissions, predict thermal comfort and air quality etc.

  An important design feature of the system is that the characteristics of a Design is compared to Benchmark values, and that the features of the Design are then scored and weighted. Results are meaningless unless the given national team has first established the benchmark values, adjusted scoring guides and adjusted the weights, so they are relevant to its region.

The current version of the system is GBTool 2005.  

Features include:

• Covers a wide range of sustainable building issues, not just green building concerns;

• Allows assessments to be carried out at all stages of the life-cycle and providesbenchmarks suited to each phase;

• Enables architects to carry out self-assessments of their designs, and enables third
parties to provide certification of operational performance;

• Allows third parties to establish weights to reflect the varying importance of issues by
occupancy type in each region;

• Allows generic benchmarks to be replaced by local ones, in local languages;

• Handles up to three building types, separately or in a mixed-use project;

• Handles new and existing construction, or a mix of the two;

• Allows comparisons to be made with LEED and Green Globes.

You can download GBTool and all other related files after filling in the Registration Form below.

Two sets of zipped GBTool files are provided with "xxx" indicating the date

1. one with example data ( )

 2. other with no project data ( )

and additionally:

  the example of a single occupancy building with un-needed fields hidden - see
( )

the GBTool Notes file (relevant to the previous version) provides information on the structure and operation of the system ( GBTool_notes_xxx.pdf ).

and the unlocked GBTool Demo version with some locked data in project description and weighting ( in its separate folder ).

 IMPORTANT NOTE! Click here before downloading


GBC2k5 Downloading Area
For further information, contact Nils Larsson, GBC coordinator, at, or your national team representative.

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