Covering Morden
Our coverage around Morden (SM4) also includes Mitcham (1 miles to the east) and Wimbledon.
Homes in London
Terraced houses dominate many London neighbourhoods, so most projects involve shared walls, narrow access and a party wall process. Conservation areas are widespread, and some boroughs have their own mansard and basement guidance.
What do you get with a side return extension?
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.
- Party wall notices and surveyor liaison
- Structural steel to remove the side wall
- Drainage and new gully positions
What will a side return extension cost?
Guide prices for side return extensions, including VAT where it applies. Your fixed price is confirmed in writing after the survey.
| 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 Morden?
Projects in England go through two separate checks. Planning (or confirmation that the work is permitted development) comes from the district, borough or unitary council, and building regulations approval comes from the council’s building control team or a registered building control approver. Where work touches a shared wall or digs near a neighbour’s foundations, the Party Wall etc. Act 1996 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. Deeper extensions, up to 6 m or 8 m, need prior approval from the council first.
What can affect a side return extension?
- Glazed roofs need careful detailing against the neighbour’s wall.
- Many terraces sit in conservation areas, where side extensions need planning permission.
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.
- 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.
What people ask before starting
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.
Is a glazed roof too hot in summer?
Modern solar-control glass and a mix of glazed and solid roof keep it comfortable. We advise on the balance during design.
Can you visit a house in Morden 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 Mitcham
- Side return extensions in Wimbledon
- Side return extensions in Carshalton
- Side return extensions in New Malden
Learn more about side return extensions, or see every project we cover in Morden.

