When a UK loft conversion needs planning permission vs permitted development in 2026 — volume limits, dormers, conservation areas, and how to check. This guide is written by PG Property Repairs and Renovations, an FMB and TrustMark accredited building company based in Worthing, using real costs and timescales from projects completed across Worthing, Lancing, Shoreham, Brighton and the wider West Sussex area.