URBASSS was a major EPSRC funded research project which studied the impact of urban form on carbon emissions from transport, energy consumption and accessibility. The work contributed to a growing body of research in this area and provided empirical proof of sustainable settlement size thresholds. It also provided guidance on the level of strategic housing, services and facilities provision required to support sustainable communities. It produced a GIS model to calculate the energy consumption, emissions and accessibility created by a range of development options and the introduction of new transport systems / services.