Barn conversion timeline
Build-cost bands are the site's own indicative model, inflated to a Q2 2026 footing via the ONS Construction Output Price Index (April 2026). Class Q rules current to the 21 May 2024 GPDO amendment.
A typical UK barn conversion runs 18 to 24 months end to end. Class Q route can compress to 14-18 months on a sound barn; full planning with listed-building consent regularly extends to 26-30 months.
The five phases
- Feasibility and design (8-16 weeks): survey, structural appraisal, RIBA Stage 0-2.
- Planning (8-24 weeks): Class Q 56 days + responses, or full planning 13 weeks + conditions discharge.
- Tender and pre-construction (8-12 weeks): RIBA Stage 4, contractor tender, building control.
- Construction (28-50 weeks): strip-out, shell, M&E first fix, internal fit, snagging.
- Completion and VAT reclaim (4-12 weeks): completion certificate, six-month VAT431C window.
Where programmes slip
- DNO three-phase upgrade lead time (12-26 weeks).
- Bat survey window (active May to September; missed surveys delay 8-12 months).
- Listed-building consent revisions (conservation officer response cycles).
- Welsh slate or hand-made tile supply.
Sources cited on this page