The EPSRC funded ReVISIONS research project developed an integrated economic and spatial modelling framework for testing regional spatial planning policies in combination with decentralised infrastructure options for energy, transport, water and waste. It forecast the trend over a 30 year period and compared this against alternative spatial planning policies and infrastructure scenarios. The alternative spatial policies included either compaction within existing urban areas, or market-led urban expansion. The infrastructure policies ranged from cost effective measures to those with the greatest environmental benefits. The spatial planning policies would result in different urban densities with compaction being mainly urban flats and market-led being mainly suburban houses. Higher density areas have lower demands for heating, water, land and travel, whereas lower densities have more space for green supply-side technologies such as solar energy, rainwater harvesting and recycling.
The integrated modelling framework included a land use and social accounting model (LUISA) which was funded by the East of England Development Agency as part of the research project. LUISA includes the whole of the UK with the wider south east regions modelled at local authority district scale. It is based on input-output socio economic accounting tables linked to random utility discrete choice modelling of spatial location and travel behaviour. It includes a detailed representation of the elasticities of land value versus density of floorspace per employment and household type. The urban land per district and transport networks are input to the model to represent the spatial planning policy and the model allocates the employment and households to the districts.
These employment and household densities are converted into the building stock using a statistical method developed from the English House Condition Survey data. The building stock is represented as 1 hectare 3D tiles that include the building and plot dimensions, the demands for energy, water and waste and the potential for decentralised supply. These generic 3D tiles were very useful as a medium for multidisciplinary research on buildings, energy, transport, water and waste. Combinations of retrofitting and renewable technologies were formulated for the tiles according to the technology scenarios.
The model forecasts the prices of land and floorspace and the travel times and costs. It shows that the spatial planning options would have an impact on household costs of living and industrial production costs. Market-led expansion tends to reduce prices, whereas compaction tends to increase prices. The socio-economic impacts are assessed using the Hicks compensating variation method for those factors that are unable to pass on the changes in prices to other factors within the modelled area. These are the exporting industries and the unemployed or inactive/retired households. Outputs from the LUISA model for the base year and the forecast year are used to calculate the amount of money that would be needed to compensate these factors for their change in utility. The paper compares the socioeconomic impacts of spatial planning policies against the environmental benefits and costs of decentralised infrastructure using the example of retrofitting and decentralised energy supply technologies for domestic buildings.