Covering Letchworth Garden City
Our coverage around Letchworth Garden City (SG5, SG6) also includes Hitchin (3 miles to the south-west) and Stevenage.
Homes in the East of England
Across the East of England, newer estates often have integral garages and room for rear extensions, while older towns have Victorian terraces and conservation areas that shape what can be built.
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.
- Party wall notices and surveyor liaison
- Structural steel to remove the side wall
- Drainage and new gully positions
How much should I budget for a side return extension?
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 |
How is a side return extension approved in Letchworth Garden City?
English projects need planning clearance from the local council, building regulations sign-off from building control, and party wall notices where the work is on or near a shared boundary. We prepare and manage all three.
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 can affect a side return extension?
- Most side returns touch a shared boundary, so the Party Wall etc. Act 1996 usually applies in England and Wales.
- Many terraces sit in conservation areas, where side extensions need planning permission.
How does the project run?
- Start with a conversation. A short call or the online form is enough for us to understand what you want to build.
- We visit and measure. A surveyor checks the house, the boundaries and the ground, and discusses what is realistic.
- Design and fixed price. You get drawings and a written price for the agreed specification before anything is ordered.
- Build and hand over. Our teams build to the programme, building control inspects, and you get the completion paperwork at the end.
Questions about a side return extension in Letchworth Garden City
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.
How do I get a price for side return extensions in Letchworth Garden City?
Use the guide price tool for a ballpark figure, then book a visit for a fixed written price for the agreed specification.
Side return extensions in nearby towns
- Side return extensions in Hitchin
- Side return extensions in Stevenage
- Side return extensions in Luton
- Side return extensions in Welwyn Garden City
Learn more about side return extensions, or see every project we cover in Letchworth Garden City.

