From the desk of Chris Lee
The CSBR Site and Building Carbon Calculator tool is intended to assist site developers, building designers, facility owners and operators with the calculation of their carbon footprint for their site and building development. For new projects, the tool is designed to assist architects and developers in estimating the greenhouse gas impacts of alternative design decisions in the early phases of design. The tool is also designed to determine the carbon footprint of existing buildings.
You can download the calculator from the U of M website.