House Extensions
in Cobham

On the Burhill Estate, where mostly two-storey houses stand in very large plots, there may be room for a double-storey or wrap-around extension, which typically takes 16 to 24 weeks to build. For the terraced cottages and former council houses north and east of the centre, a single-storey rear extension of 10 to 14 weeks may be the more practical shape. The council's community workshops recorded residents' worry that new buildings often dominate their plots, which makes proportion as important as floor area.

In the Green Belt, which surrounds the settlements to the south and east and takes in Downside, an extension that needs planning permission must stay proportionate to the original house; across Elmbridge it covers 57% of the borough. Inside any of the five conservation areas, side and two-storey extensions need planning permission, and every householder application needs the Elmbridge Design Code Checklist. Near the River Mole, the Environment Agency's flood map for planning shows whether a flood risk assessment is likely to be needed. From 1 April 2027 applications are decided by the new East Surrey Council, and the right planning route for each house is agreed with you before design begins.