Why it fails
The leftover sites on the list are real. Flood, cleanup costs, missing nature space and other problems mean most of them cannot take the houses.
Contamination and cleanup
Old gasworks, tips, railways and yards often cost more to clean than the homes would sell for in cheaper East of England towns.
Flood risk
Fenland, the Broads and the Essex and Norfolk coasts have extensive Flood Zone 3. Functional floodplain is not a housing land supply.
Green Belt
Green Belt is extensive in Hertfordshire and western Essex, but most leftover land sits in towns that are inset from it. Checked against the boundary, this is a real but small discount.
Housing cost
Cleaning a leftover site, lifting it out of the flood, and finding room for nature either stop the homes or get loaded onto the house price.
No room for nature
Mandatory 10% biodiversity net gain needs habitat. Most East of England brownfield plots are too small and too built-out to provide it on site.
Nutrient neutrality
Natural England's 2022 advice froze overnight accommodation across Norfolk and in the Stour and Orwell catchments until mitigation credits exist.
Permission is not delivery
A brownfield register row with planning permission is still only paper capacity. Historically only a sliver of register capacity was under construction.
Split ownership
Mixed, unknown or several owners keep leftover sites sitting there even when the land looks suitable.
Still needed as industry
A share of register land is working or strategically useful employment land. Counting it as housing capacity double-counts the same plot.