House Extension Builders: UK Cost Guide & Pricing 2025

## Meta Description Comprehensive UK pricing guide for house extension builders in 2025. Real costs per m², what quotes should include, plus expert tips on finding reliable contractors. ## Key Takeaways Single-storey house extension builders typically charge £1,800–£2,500 per m² across the UK, with London prices reaching £3,000+ per m² Builder day rates range from £150–£250 outside London, rising to £200–£350 in the capital, but project quotes are more common for extensions A comprehensive quote should include VAT, materials, labour breakdown, timescales, payment schedule, and building regulations approval process UK requirements Checking credentials through the Federation of Master Builders, Checkatrade, or TrustMark can significantly reduce your risk when hiring Extensions under 4 metres for single-storey or 3 metres for two-storey may qualify as permitted development, saving £500–£1,200 on planning costs Planning a home extension represents one of the most significant investments you'll make as a homeowner. Finding the right house extension builders can mean the difference between a dream space that adds substantial value to your property and a costly nightmare that drags on for months. We've compiled this comprehensive cost guide to help you navigate the complex landscape of extension pricing, builder selection, and project management across the UK. The house extension market has evolved considerably since 2023. Material costs have stabilised after the volatility of r