Velux (rooflight) loft conversion costs in Worthing for 2026: £18k–£30k. What's included, when you don't need planning, and what drives the final price. 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.