This report documents the work done in the project “Sustainable Workspace Performance” for Steelcase in the period of October 2006 - December 2007. Today organizations around the world are encouraging and promoting standards for environmentally efficient buildings. Interest in these “green” buildings have increased immensely, but just like financial metrics do not provide a total view of the effectiveness and efficiency of the workspace, the environmental focus tends to be one dimensional. In this project a framework and a computer-based tool was developed to demonstrate the links between the workspace and sustainability (in economic, social and environmental terms). State-of-the-art research and knowledge of workspace and sustainability issues were identified and structured. A “works like” concept model has been developed and is presented in this report. The objective of the project was to allow companies to assess their own performance of their workspace in each of the sustainability dimensions relative to their own business context. This is expected to engage and empower companies to take action and make informed sustainable decisions in the design of their workspace.