How much does an extension cost in the West Midlands?
Realistic planning-stage ranges by extension type, plus the factors that drive cost up or down.
Planning-stage cost bands
| Extension type | Indicative range | More detail |
|---|---|---|
| Single-storey extensions | From £30k–£55k+ | Single-storey extensions details |
| Double-storey extensions | From £55k–£90k+ | Double-storey extensions details |
| Kitchen extensions | From £25k–£60k+ | Kitchen extensions details |
| Rear extensions | From £30k–£55k+ | Rear extensions details |
| Side-return extensions | From £25k–£45k+ | Side-return extensions details |
| Wrap-around extensions | From £45k–£85k+ | Wrap-around extensions details |
| Over-garage extensions | From £25k–£55k+ | Over-garage extensions details |
What pushes cost up
- Large spans of glazing — sliders and bifolds, rooflights
- Premium kitchen, joinery and ironmongery
- Steel structure for big open spans
- Poor ground conditions or drainage diversions
- Underfloor heating across the whole footprint
- Bespoke roof forms or vaulted ceilings
What keeps cost down
- Simple rectangular footprint
- Standard rooflights and patio doors instead of large sliders
- Mid-range fitted kitchen rather than bespoke
- Permitted development route (no planning fees, faster start)
- Avoiding ground works on services or drains
Frequently asked questions
What is included in these prices?
Prices reflect planning-stage build cost — structure, shell, glazing and a mid-range kitchen and finish level. They exclude householder planning fees, professional design fees, VAT where applicable, and discretionary upgrades.
Why is there such a wide range?
Glazing, kitchen spec, structural complexity, ground conditions and finishes can move a project by tens of thousands. The honest answer at planning stage is a band, not a single number.
Are kitchens included?
A mid-range fitted kitchen is typically included in our kitchen-extension budgets. Premium kitchens (Bulthaup, Boffi etc) are quoted separately.
What about VAT?
Most domestic extensions are zero-rated only in very specific scenarios. Assume standard VAT applies unless your accountant or HMRC confirms otherwise.