A parametric model of residential built form for forecasting the viability of sustainable technologies

Renewable supply systems, such as rainwater harvesting and ground source heat pumps, have the potential to improve the sustainability and resilience of residential areas. However, their feasibility partly depends on the dimensions and plot areas of the dwellings, and there has been a lack of a suitable method of modelling these for future urban development. This paper therefore calibrates and validates a method of modelling how the plot areas and footprints of dwellings would vary in size. Its inputs are the total dwellings and their average density for each area type within a district. It could thereby complete a chain of urban modelling from regional to local scale for testing spatial planning scenarios. The results show that the calibration of the model is transferable between spatial scales and UK regions, and the results are validated against detailed GIS data. It is then developed into a novel parametric model to estimate how built form will affect the future potential of renewable supply systems, and this is demonstrated using rainwater harvesting as an example. It provides estimates of water-savings at district scale that are more reliable than the usual method of using discrete average dimensions per dwelling type.