Garage conversion prices UK 2026: single £8k–£15k, integral £12k–£20k, double £18k–£30k. Free cost calculator, regional prices, planning and building regs. 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.