Practical, expert-written guides on costs, planning permission, building regulations, and everything else you need to know before starting your project. Written by TCM's team with 15+ years of hands-on experience.
Typically £1,800–£3,000 per m² in London, so a 20m² extension costs £36,000–£60,000 before VAT and professional fees.
Most loft conversions qualify as Permitted Development — no planning permission needed. Key limits: 40m³ for terraced houses, 50m³ for semi-detached and detached.
A single-storey rear extension typically takes 10–14 weeks on site. A double-storey extension takes 14–20 weeks. Add 8–12 weeks for planning and design.
Yes — a well-executed loft conversion typically adds 15–25% to a property's value in London and Hertfordshire, often returning more than the build cost.
Our team is happy to answer any questions about your project — costs, planning, timescales, or anything else. No obligation, no pressure.