Covering Southampton
Alongside Southampton, we also cover Totton (4 miles to the west), Eastleigh and Fareham.
Homes in the South East
The South East has a lot of 1930s and post-war semi-detached housing, well suited to rear extensions and hip-to-gable loft conversions, alongside period properties in conservation areas that need a more careful design.
What is a side return extension?
A side return extension builds over the narrow passage that runs beside the back of many Victorian and Edwardian terraced houses, widening the kitchen or dining room by a metre or two. It is usually combined with a glazed or part-glazed roof so the deeper room still gets daylight.
- Glazed or solid roof with rooflights
- Drainage and new gully positions
- Underfloor heating ready screed if wanted
What is the guide price for a side return extension in Southampton?
Indicative costs for side return extensions. London and the South East usually sit towards the top of each range.
| 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 |
Planning and building rules in Southampton
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?
- Access is often through the house, so we plan deliveries and protect floors.
- Glazed roofs need careful detailing against the neighbour’s wall.
From first call to completion
- Start with a conversation. A short call or the online form is enough for us to understand what you want to build.
- Free site visit. We measure up, look at access, drains and the structure, and talk through options and budget.
- Price and paperwork. The design is priced line by line, and we submit the planning and building control applications.
- Build and hand over. Our teams build to the programme, building control inspects, and you get the completion paperwork at the end.
Side return extensions: common questions
How much does a side return extension cost?
Usually about £3,350 to £4,550 per square metre including VAT, which works out at around £35,000 to £55,000 for a typical side return before the kitchen.
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.
Can you visit a house in Southampton 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.
Side return extensions in nearby towns
- Side return extensions in Totton
- Side return extensions in Eastleigh
- Side return extensions in Fareham
- Side return extensions in Cowes
Learn more about side return extensions, or see every project we cover in Southampton.

