PPS 12 Housing in Settlements·Page 23·66
Residual Housing Need Identification
Land identified beyond the urban footprint should only address residual housing need remaining after accounting for urban capacity yield, windfall allowance, and already constructed or committed dwellings.
The need, if any, for further identification of land beyond the urban footprint in a settlement will be that which is residual after taking account of the urban capacity yield, windfall allowance and dwellings already constructed or committed.
Source — /Users/richardhill/Documents/planning-arch-project/data/documents/regional/PPS 12 - Housing in Settlements.pdf