Published 25 April 2026 · Updated 14 May 2026
By Jon Thompson, Director — Living Design & Build Ltd, FMB-member builder, Bridgnorth
If you are planning a house extension in Shropshire or the West Midlands, the first question is almost always: how much is this going to cost? Twenty years of building across Bridgnorth, Stourbridge, Wolverhampton, Telford and Halesowen has given us a clear picture of where 2026 prices land. This guide breaks it down honestly — including the factors that push a quote up or down.
The headline numbers (2026 prices)
These are typical fixed-price ranges we quote on real projects across Shropshire and the West Midlands. They include design, structural calculations, Building Regulations submission, and all trades through to handover. They do not include planning fees, party-wall surveyors, or kitchen/bathroom appliances unless specified.
- Single-storey rear extension (20m²): £40,000–£60,000
- Single-storey rear extension (30m² with lantern roof and bi-folds): £55,000–£80,000
- Side-return extension (15m²): £35,000–£55,000
- Wrap-around extension (25–35m²): £70,000–£110,000
- Two-storey side or rear extension (40–60m² total): £85,000–£140,000
- Garage conversion (integral): £18,000–£32,000
- Loft conversion (Velux only): £30,000–£45,000
- Loft conversion (dormer with en-suite): £45,000–£75,000
What pushes the price up
Two extensions with the same square footage can quote 30% apart. Here is what usually causes the gap:
- Glazing specification — a lantern roof with bi-folds adds £8,000–£15,000 over a flat roof with standard French doors.
- Kitchen fit-out — a £6,000 kitchen versus a £25,000 kitchen with stone worktops and integrated appliances.
- Existing wall removals — opening up the back of the house with a long steel beam adds structural engineering and steelwork cost.
- Ground conditions — sloping plots, high water tables, or shallow foundations on neighbouring walls add to groundworks.
- Finish level — engineered oak flooring, underfloor heating, smart wiring, in-ceiling speakers all stack quickly.
- Listed-building or conservation area — heritage requirements and traditional materials add cost.
What keeps the price down
- Building under permitted development where possible (avoids the £258 planning application fee and 8-week wait).
- Keeping the existing kitchen layout and reusing units in the new space.
- Choosing a simple flat or mono-pitch roof rather than a hipped or gabled design.
- Standard window and door sizes instead of bespoke aluminium.
- Single supplier for kitchen, bathroom and flooring (one delivery, one fit, one snag list).
What's included in a Living Design & Build quote
- Architectural design and planning portal submission
- Structural engineer calculations and steelwork specification
- Building Regulations submission and inspections
- Party-wall notices where applicable
- All trades — groundworks, brickwork, carpentry, roofing, plumbing, electrics, plastering, decoration
- Project management and weekly client updates
- Final completion certificates and handover pack
Frequently asked questions
How long does an extension take to build?+
Single-storey extensions typically take 12 to 16 weeks from site start. Two-storey extensions run 16 to 24 weeks. Wrap-arounds usually land at 18 to 22 weeks. We provide a written week-by-week programme before contracts are signed.
Will an extension add value to my home?+
In Shropshire and the West Midlands, a well-designed single-storey rear extension typically adds 5–11% to property value. Two-storey extensions add 10–15%. Loft conversions with an en-suite usually return more than they cost in suburbs with good schools (e.g. Pedmore, Wombourne, Tettenhall).
Do you need planning permission?+
Not always. Many single-storey rear extensions fall under permitted development. Two-storey extensions, anything over 4m on a detached home (3m on a semi), and any work in a conservation area or on a listed building needs full planning permission. We assess this on the first visit.
Can I stay in the house during the build?+
Yes — most clients do. We dust-sheet the working area, keep services live, and program disruptive trades (plastering, screeding) for when you can be out. For full kitchen-diner remodels you may want a 1–2 week break during the messiest phase.
Ready for a fixed-price quote?
We're an FMB-member builder based in Bridgnorth, covering all of Shropshire and the West Midlands. Twenty years in, 1,000+ projects done, 4.8/5 on Google. Request a free site visit and we'll give you a written fixed-price quote within seven days.