A standard single-storey extension in the South East, the region Reading sits in, starts from about £30,000 in BestBuilders' 2026 index, against £33,500 in London and £25,000 in the Midlands. It is a modelled starting price, so use it as a budget floor and confirm it with local quotes.
A standard single-storey extension in the South East region starts from about £30,000, against £33,500 in London, according to BestBuilders’ 2026 extension index. Reading falls inside that region, but nobody we found publishes a price for Reading itself, so use the regional figure as a floor for your budget and confirm it with local quotes.
How South East compares
| Region | "Starting from" | Against South East |
|---|---|---|
| London | £33,500 | £3,500 more |
| South East (Reading) | £30,000 | baseline |
| Southern (Hants, Wilts, Dorset) | £27,500 | £2,500 less |
| Midlands | £25,000 | £5,000 less |
| South West | £23,000 | £7,000 less |
These figures come from one vendor’s model, not from quotes: BestBuilders’ 2026 extension index says its prices are rounded, “starting from” figures built from national cost guides and a regional labour index, for budgeting rather than quoting. Other sources publish higher numbers for the same job, so treat the table as a floor.
What the gap is made of
BestBuilders says it builds each region’s price from national cost guides plus a regional labour index. That fits how the trade works: bricks, timber and roofing cost the same wherever you are, so the difference between Reading and London is mostly what a builder charges for a day’s work. For the national picture and what drives it, see our guide to how much a house extension costs in the UK.
Budgeting for Reading
- Start from £30,000 for a basic single-storey build and expect more once you add a better finish, bifold doors or a kitchen.
- Ask every builder for an itemised quote that separates labour, materials, fees and a contingency.
- Check planning first. Planning applications in Reading go to Reading Borough Council, so check its guidance as well as the national rules. Our guide to planning permission for a single-storey extension covers the limits that let many rear extensions skip a planning application.
Finding a builder in Reading
See the top 5 builders in Reading for firms checked on trading history and independent reviews, and read how we choose for the method. Ask each for recent, similar work you can see in person.
For other towns, browse our top 5 builders across the UK.
Frequently asked questions
How much does an extension cost in Reading?
BestBuilders' 2026 index starts a standard single-storey extension in the South East region at £30,000, with a typical range of £30,000 to £60,000. It is a modelled "starting from" figure, not a quote, and no source we found publishes prices for Reading itself.
Is Reading cheaper than London for an extension?
On that index, yes: the starting price is £30,000 against £33,500 in London, a gap of £3,500 or about 10%. The difference is almost entirely labour, because materials are priced nationally.
Why does a Reading extension cost more than the national average?
Reading sits in the South East, where the index starts a single-storey extension at £30,000 against £22,000 to £25,000 in many other regions. The index attributes the spread to a regional labour index rather than material prices.
Who decides planning applications in Reading?
Reading Borough Council. Many single-storey rear extensions fall under permitted development, but check the size limits, and ask the council if an Article 4 Direction or conservation area applies to your street.
Related guides
More regional costs guides · All builders guides
About the author
Stu Clark
Stu spent over 15 years in the trades, working as a plumber before running his own plumbing and bathroom renovation company with a team of eight. He founded Top5Trades to give homeowners the kind of shortlist and straight advice you would get from someone who has actually done the work. More about us →