Cost guide
How much does a bungalow extension cost?
The published per-m² rate for extending a bungalow, and what a dormer loft addition adds on top.
A single-storey bungalow extension costs around £2,750 per m² on average, according to Checkatrade, while MyBuilder quotes a wider general range of £1,250-£4,000 per m² depending on specification. Checkatrade also quotes an average dormer bungalow loft extension cost of £50,850, based on a 30m² addition.
Last updated 20 August 2026
| Range | ||
|---|---|---|
| Checkatrade average, per m² - published as a single average figure | £2,750 | Per m² |
| General range, per m² | £1,250-£4,000 | Per m² |
| Dormer loft addition, total - based on a 30m² addition | £50,850 | Total project |
Sources: Checkatrade (per m² average and dormer figure, checked August 2026), MyBuilder (general per m² range, checked August 2026)
Key points
- Whether the project extends outward, adds a dormer loft addition upward, or both - a bungalow is one of the few property types where going up is routinely part of the answer.
- Plot width - bungalow plots are often wider than a terraced house's, which can make the half-original-width side extension rule less restrictive.
- Roof design, since a bungalow's roofline is usually more involved in the project than a two-storey house's.
- Specification tier - fittings, glazing and finish move the per-m² rate within the range above.
These are general published ranges, not a quote. Get an estimate based on your own project.
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Other cost guides
More published cost ranges
How much does a loft conversion cost?
Published industry ranges by conversion type, so you can budget sensibly before getting a quote.
How much does a house extension cost?
The published UK per-m² rate for a single-storey extension, and what actually moves it.
How much does a two storey extension cost?
Published per-m² rates by build quality, and what a typical two-storey extension runs in total.
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