House Extension Cost Guide — Manchester
A straightforward breakdown of what a house extension costs in Manchester and the North West, what changes the price, and how to budget before you get a formal quote.
What does a house extension cost?
VP / GUIDE / EXT
Single-storey extension
Standard finish
£2,500–£3,000
per m²
Double-storey extension
Standard finish
£2,200–£2,700
per m²
Wraparound / side return
Standard finish
£2,700–£3,200
per m²
What changes the price
- Size & footprintLarger extensions cost more in total, but the price per m² usually drops slightly, since groundworks and roof structure don't scale exactly with floor area.
- Structural complexityRemoving load-bearing walls, steel beams, and working around existing drainage or foundations all add cost before any finishing work starts.
- Finish levelStandard fittings versus bespoke joinery, underfloor heating, bi-fold or sliding glass doors and higher-spec kitchens can shift the total significantly.
- Planning routePermitted Development is faster and cheaper than full planning permission; projects needing a full application carry extra time and fees.
- Site accessRestricted access, shared driveways or working in a terrace can increase labour time and material handling costs.
- Party wall noticesSide-return and wraparound extensions often run along a shared boundary, which can trigger a Party Wall Act notice. Check with our free party wall checker before finalising your budget or timeline.
These are indicative estimates for budgeting, not a fixed quote, and exclude VAT and professional fees (architect, structural engineer, Building Regulations). Final pricing depends on the drawings and full scope of works agreed for your project, and can vary from these ranges once a site visit and detailed design are complete.
Work out a rough budget
Pick the type of extension and drag to its approximate floor area. It uses the per-m² ranges above, so it's a starting point for budgeting, not a quote.
House extension costs, explained
See the extensions & renovations service for how we deliver them.
Is this the price I'll actually pay?
No. These are indicative ranges to help you budget before speaking to us. Your actual price depends on the specifics of your project, and we always provide a detailed, itemised written quote after a site visit rather than a generic estimate.
Does the price include planning permission and Building Regulations?
Planning and Building Regulations costs, where needed, are itemised separately in your written quote rather than hidden inside the build cost, so you can see exactly what you're paying for. Not sure whether your project needs planning permission? Our free planning permission checker gives an indicative answer in under two minutes.
What's not included in a typical extension quote?
Furniture, most appliances and landscaping beyond the immediate build area are usually excluded unless specifically requested and priced in. VAT and professional fees (architect, structural engineer, Building Regulations) also sit outside the core build cost.
How can I keep costs down without cutting corners?
Staying within Permitted Development limits avoids planning application time and fees, keeping the design simple (avoiding complex rooflines or structural changes) reduces labour cost, and agreeing the full specification before work starts avoids costly mid-project changes.
More cost guides and tools
Want an accurate price for your extension?
Book a free site visit and we'll give you a detailed, itemised written quote, not a rough estimate.
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