Covering Northamptonshire
Our single-storey extensions service in Northamptonshire covers Northampton, Corby, Kettering and Wellingborough and more.
Homes in the East Midlands
Housing in the East Midlands includes Victorian terraces, inter-war semis and newer estates, with stone-built villages in some areas where conservation controls apply.
What does a single-storey extension involve?
A single-storey extension adds one level of new floor space to the back or side of a house, usually to open up a kitchen, dining or family room. It is the most common way to gain space without moving, and many can be built without a planning application.
- Planning or lawful development certificate where needed
- Brickwork, roof, glazing and insulation
- First-fix and second-fix electrics, plastering and making good
How much should I budget for a single-storey extension?
Indicative costs for single-storey extensions. London and the South East usually sit towards the top of each range.
| Single-storey extensions | Guide price incl. VAT |
|---|---|
| Standard specification | £2,600 to £3,000 per m² |
| Good specification | £3,000 to £3,500 per m² |
| High specification | £3,500 to £4,000 per m² |
Do you need permission for a single-storey extension in Northamptonshire?
In England we deal with the council’s planning team for permission or a lawful development certificate, with building control (the council or a registered building control approver) for inspections, and with neighbours under the Party Wall etc. Act 1996 where it applies.
In England a single-storey rear extension can often go ahead under permitted development: up to 3 m deep on an attached house or 4 m on a detached one, no higher than 4 m, with eaves no higher than 3 m within 2 m of a boundary.
What should I think about before starting?
- Large glazed areas need to meet energy rules, which can shape the size of doors and rooflights.
- Kitchens and doors have long lead times, so we order them early.
How does the project run?
- Send us the details. Give us a postcode, a rough idea of size and some photos, by phone, form or the guide price tool.
- Free site visit. We measure up, look at access, drains and the structure, and talk through options and budget.
- Design and fixed price. You get drawings and a written price for the agreed specification before anything is ordered.
- We build it. Work follows an agreed programme, with inspections at each stage and a final sign-off.
Your questions answered
How much does a single-storey extension cost?
Most single-storey extensions cost about £2,600 to £4,000 per square metre including VAT, depending on specification, glazing and ground conditions. We give a fixed price in writing for the agreed specification after the survey.
Do you need to dig up the drains?
Sometimes. If a public sewer runs under the extension, the water company has to agree a build-over or a diversion. We check this at survey stage.
Can you visit a house in Northamptonshire to quote?
Yes. After a short call we arrange a site visit to measure up and agree what the design needs to do, then send a written price.
Single-storey extensions near Northamptonshire
- Single-storey extensions in Northampton
- Single-storey extensions in Corby
- Single-storey extensions in Kettering
- Single-storey extensions in Wellingborough
- Single-storey extensions in Rushden
- Single-storey extensions in Daventry
- Single-storey extensions in Brackley
- Single-storey extensions in Towcester
Learn more about single-storey extensions, or see every project we cover in Northamptonshire.

