BCIS build cost per sqm
- Estate housing, lower quartile: 1,379 £/sqm
- Estate housing, median: 1,559 £/sqm
- Estate housing, upper quartile: 1,785 £/sqm
- Flats, median: 1,832 £/sqm (quartiles 1,599 to 2,225)
BCIS figures rebased to Cotswold, as reprinted in Cotswold District Local Plan Viability Assessment (Quintic Advisory for Cotswold District Council, May 2026, Appendix 4). BCIS data last updated 16 May 2026, rebased to Cotswold (location index 101). 15-year default sample. BCIS rates are gross internal floor area, include preliminaries and exclude external works, fees, contingency and VAT. BCIS itself is subscription-only; this is the most recent public reprint we found for the region.
GDV working band
Resale GDV 360 to 600 £/sqft (low to high). Mid 440 £/sqft. Sense-check against current Land Registry Price Paid postcode-area aggregates before committing a bid.
Bristol pulls the average up; Cornwall second-home premium adds tail risk.
Cornwall second-home premium policy
- Cornwall Council's 100 percent second-home council tax premium (doubling the annual bill, in force from 1 Apr 2025) hits resale velocity in PL postcodes.
- Apply a velocity haircut (extra 3 to 6 months on the sales period) when modelling Cornwall self-builds.
- Bristol BS postcodes are unaffected and continue to anchor SW GDV upside.
Small-sites threshold
- Most SW local plans set the small-sites threshold at 10 dwellings net additions.
- BNG is a separate area test from the local-plan dwelling threshold: sites up to 0.2ha with no on-site priority habitat are exempt from 6 Aug 2026.
Open the workbench with these rates
Cells show profit-on-cost percentage at each GDV stress / build-cost shock pair. Cells below your target PoC turn amber-warm; cells below 10 percent abort.