Home extensions
More space, the right way.
Verified builders for single storey, double storey, wraparound and side-return extensions. You choose who quotes. One appointed builder, never a flood of cold calls.
01
What "Extension" covers
Verified specialists who handle the full scope, not one slice of it. You choose who quotes; one appointed builder, one point of contact.
Single storey rear and side-return extensions
Double storey extensions and over-garage builds
Wraparound extensions and reconfigured ground floors
Permitted-development and full planning routes
02
What we typically include, and don't
A clear scope is the difference between a smooth project and an expensive argument.
Included
In scope- Architectural drawings and structural calcs
- Build, services, finishes and a typical contingency
Typically not included
Priced separately- Furniture, white goods, soft furnishings
- Bespoke joinery beyond a standard fit-out
- Landscaping the surrounding garden (priced separately)
03
Realistic cost range
Single storey rear extensions typically £55k to £140k.
The Cost Planner gives you a postcode-adjusted range with a clear breakdown of what’s included. Use it before you talk to a builder so you walk in knowing your numbers.
04
Common questions
Direct, plain answers. No marketing copy.
How much does a typical extension cost in the UK?
A single storey rear extension typically lands between £2,000 and £3,500 per square metre, including design, build and finishes. Use the Cost Planner for a postcode-adjusted range.
Do I need planning permission?
Many extensions fall under permitted development, but it depends on size, neighbours, conservation area, and listed status. Builders on Compare Builders flag this in their first conversation; lawful-development certificates are a common first step.
How long does an extension take to build?
A single storey rear extension typically runs 10 to 14 weeks on site once permissions are granted. A wraparound or double storey is more like 14 to 22 weeks. Lead times for design + planning add another 8 to 16 weeks before you start.
By area
Builders by area
Public-record profiles of building firms that have not joined Compare Builders yet, by county. Each page is unclaimed and unverified until the business claims it.
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