Policy information sourced from Hammersmith & Fulham Planning Guidance
FR4 Requirements for self contained basement flats
New self-contained basement flats will not be permitted in the Environment Agency’s Flood Zone 3 areas where there is a risk of rapid inundation by flood waters in the event of a breach of the river’s flood defences or in surface water flooding hotspots where the flood hazard rating is defined a significant or higher in the SWMP, unless a satisfactory means of escape can be provided.
For more information please see the Hammersmith & Fulham Planning Guidance