GUIDE
Loft conversion ranges
Last checked September 2026 · Compiled UK mid bands, before spec, region, VAT and extras
A rooflight conversion and a mansard are not the same job. This lab prices lofts by useful floor area. Compiled 2026 mid £ per m² before factors:
- Velux / rooflight: about £1,550 / m² (default 22 m²)
- Rear dormer: about £1,850 / m² (default 28 m²)
- Hip-to-gable: about £2,050 / m²
- L-shape dormer: about £2,150 / m²
- Mansard: about £2,400 / m²
Tick an ensuite, a proper staircase, planning, Party Wall or professional fees if those apply. Treat the mid point as a planning number. Collect two or three written quotes on the same drawing.