Covering Northamptonshire
We cover Northamptonshire, including Northampton, Corby, Kettering and Wellingborough, and the towns around them.
Homes in the East Midlands
The East Midlands combines red-brick terraces in the cities with a lot of post-war and modern estate housing, so rear extensions, garage conversions and loft conversions are all common.
What does a side return extension involve?
Side returns are small in area but heavy in detail: party walls, a glazed roof, and steelwork to take out the original back wall. We design the roof for light and drainage, agree the party wall process early, and keep the work tidy because access is often through the house.
- Structural steel to remove the side wall
- Glazed or solid roof with rooflights
- Drainage and new gully positions
How much should I budget for a side return extension?
Use these ranges to budget for side return extensions; the survey turns them into a fixed price for the agreed specification.
| Side return extensions | Guide price incl. VAT |
|---|---|
| Standard specification | £3,350 to £3,700 per m² |
| Good specification | £3,700 to £4,150 per m² |
| High specification | £4,150 to £4,550 per m² |
Do you need permission for a side return 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?
- Most side returns touch a shared boundary, so the Party Wall etc. Act 1996 usually applies in England and Wales.
- Access is often through the house, so we plan deliveries and protect floors.
From first call to completion
- Tell us about the project. Call, use the guide price tool or send the form with a few photos and a postcode.
- Free site visit. We measure up, look at access, drains and the structure, and talk through options and budget.
- Drawings, approvals, written quote. We prepare the design, apply for the approvals it needs, and give you a fixed price in writing.
- We build it. Work follows an agreed programme, with inspections at each stage and a final sign-off.
Questions about a side return extension in Northamptonshire
Does a side return need planning permission?
In England it can be permitted development if it is single storey, no higher than 4 m and no wider than half the original house. Conservation areas are the main exception.
Will I need a party wall agreement?
Most likely, because the new wall usually sits on or near the boundary. We serve the notices and work with your neighbour’s surveyor if one is appointed.
Do you work in Northamptonshire?
Yes. Northamptonshire is within our coverage for side return extensions, along with nearby Northampton and Corby.
Side return extensions in nearby towns
- Side return extensions in Northampton
- Side return extensions in Corby
- Side return extensions in Kettering
- Side return extensions in Wellingborough
- Side return extensions in Rushden
- Side return extensions in Daventry
- Side return extensions in Brackley
- Side return extensions in Towcester
Learn more about side return extensions, or see every project we cover in Northamptonshire.

