What is a single-storey extension?
A single-storey extension is a ground-floor addition, usually at the rear of a house, that enlarges a kitchen, living or dining space. Most are built with cavity walls on concrete foundations and finished with a flat roof and roof lantern or a pitched tiled roof.
How much does a single-storey extension cost in Ipswich?
In Ipswich, a single-storey extension typically costs £2,050–£3,050 per m² of floor area, including VAT at 20% (standard rate). For a typical 20 m² project that is roughly £41,000–£61,000. That range is adjusted for the East of England, where domestic building work typically costs around 6% above the national average. Design, structural calculations and council fees are extra.
| Size or type | Guide range |
|---|---|
| Smaller project (14 m²) | £28,500–£42,500 |
| Typical project (20 m²) | £41,000–£61,000 |
| Larger project (28 m²) | £57,500–£85,500 |
| Rate per m² | £2,050–£3,050 |
The main things that change the cost:
- Roof type and the size of any lantern or roof windows
- Kitchen, flooring and finishes, which we can include or leave to you
- How much of the existing house is opened up
- Floor area and the length of new wall
Use the guide price tool to see how size and specification change the figure, then ask for a written, itemised quote.
Do you need planning permission for a single-storey extension in Ipswich?
The approval route for Ipswich is set by planning law in England. In England a single-storey rear extension is often permitted development: broadly up to 3 metres deep on a semi-detached or terraced house and 4 metres on a detached house, no higher than 4 metres, with eaves no higher than 3 metres within 2 metres of a boundary, and covering no more than half the garden. The larger home extension scheme allows up to 6 or 8 metres if you notify the council first and neighbours have a chance to comment. In conservation areas, National Parks and National Landscapes the larger home extension route, side extensions and cladding are not permitted development. Flats and houses whose rights have been removed need a planning application, and listed buildings need listed building consent.
Where work involves a shared wall, building on the boundary, or digging foundations within 3 metres of a neighbour’s building and deeper than its foundations (or within 6 metres for deeper work), the Party Wall etc. Act 1996 applies and notices must be served before work starts.
Our first visit includes a check of your planning history, so you know the route before paying for drawings.
What we handle
Handled as part of most single-storey extensions:
- Doors, windows and roof glazing installed
- Foundations, drainage and any build-over agreement
- Knock-through to the existing house with steel beams
- Measured survey and design drawings
- First and second fix electrics, heating and plastering
- Structural calculations for steels and lintels
How long does it take?
The build itself usually takes 10 to 14 weeks on site for a typical rear extension, after approvals. Allow time beforehand for drawings and approvals, usually 6 to 12 weeks.
Building in Ipswich
Many towns in the East of England have estates built since the 1970s, where garage conversions and rear extensions are popular.
We work across Ipswich and neighbouring areas such as Harwich, Felixstowe and Stowmarket. Postcodes we cover in Ipswich include IP1, IP3 and IP4.
How it works
- 01
Visit and measured survey
A free visit to understand the project, check access and take measurements.
- 02
Design and pricing
Design options, then a fixed quote based on the chosen drawings and specification.
- 03
Approvals
Planning or permitted development confirmation, building regulations and any party wall matters.
- 04
Construction and completion
We build, put right any snags and hand over the building control certificate.
Questions about single-storey extensions in Ipswich
How much does a single-storey extension cost in Ipswich?
In Ipswich, a single-storey extension typically costs £2,050–£3,050 per m² of floor area, including VAT at 20% (standard rate). A typical 20 m² project comes to roughly £41,000–£61,000. Your fixed price depends on the survey and drawings.
What is a build-over agreement?
If a public sewer runs within 3 metres of the extension, the water company normally has to agree to the work before it starts. We check sewer records during design and apply where needed.
Do you build single-storey extensions in Ipswich?
Yes. We build single-storey extensions across Ipswich, including postcodes IP1, IP3 and IP4. Every project starts with a free home visit.
Is VAT charged on an extension?
Yes. Building work on an existing home is standard-rated, so VAT at 20% applies. Our guide prices include it.
How long does a single-storey extension take?
Once approvals are in place, a typical rear extension takes 10 to 14 weeks on site. Design and approvals usually take another 6 to 12 weeks beforehand, depending on whether a planning application is needed.