## Introduction Planning a home extension can feel overwhelming, but our comprehensive house extension guide breaks down everything UK homeowners need to know about costs, planning permission, and project management. With property prices remaining high across the country, extending your existing home often makes more financial sense than moving. We've worked with hundreds of professionals in our directory to compile realistic pricing, regulatory requirements, and money-saving strategies that actually work. ## Key Takeaways Single storey extensions typically cost £1,200–£2,000 per m² across most of the UK, rising to £2,500–£3,500 per m² in London Many extensions fall under permitted development rights, avoiding full planning permission requirements Loft conversions and garage conversions offer the best value-per-square-metre compared to ground floor extensions Project management is crucial — poor coordination adds 15-20% to final costs through delays and rework Getting three detailed quotes and checking building regulations compliance early saves thousands in the long run ## How much does a home extension cost in the UK? The single storey extension cost UK per m2 varies significantly based on specification and location. For a basic rear extension with standard finishes, expect £1,200–£1,500 per m² outside London. Mid-range specifications with quality fixtures run £1,500–£2,000 per m², whilst high-end builds with premium materials and underfloor heating reach £2,000–£2,500