Covering Letchworth Garden City
Alongside Letchworth Garden City, we also cover Hitchin, Stevenage (5 miles to the south) and Luton.
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 do you get with an upward extension?
The first question is whether the existing walls and foundations can carry the extra load, so we start with a structural survey. Then we design either a full first floor or a raised roof with dormers, handle planning or prior approval, and build the new storey while protecting the floor below.
- Structural survey of walls and foundations
- New first-floor structure, walls and roof
- Staircase and changes to the ground floor layout
How much does an upward extension cost in Letchworth Garden City?
Use these ranges to budget for bungalow and upward extensions; the survey turns them into a fixed price for the agreed specification.
| Bungalow and upward extensions | Guide price incl. VAT |
|---|---|
| Chalet conversion with dormers (total) | £45,000 to £85,000 |
| New first floor, standard specification | £2,200 to £2,800 per m² |
| New first floor, good specification | £2,800 to £3,300 per m² |
| New first floor, high specification | £3,300 to £3,800 per m² |
What approvals does an upward extension need in England?
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, Class AA permitted development allows an extra storey on many detached and semi-detached houses built between July 1948 and October 2018, subject to a prior approval application covering design, neighbours’ amenity and other matters.
What can affect an upward extension?
- The house is exposed while the roof is off, so the sequence is planned tightly.
- Neighbours’ light and privacy are the main planning tests.
What are the steps?
- Send us the details. Give us a postcode, a rough idea of size and some photos, by phone, form or the guide price tool.
- Survey at your house. We look at the existing structure, services and access, and agree what the design needs to achieve.
- Price and paperwork. The design is priced line by line, and we submit the planning and building control applications.
- We build it. Work follows an agreed programme, with inspections at each stage and a final sign-off.
Bungalow and upward extensions: common questions
How much does it cost to add a storey?
Around £2,200 to £3,800 per square metre of new floor including VAT, or £45,000 to £85,000 for a chalet conversion with dormers.
How long does it take?
About 12 to 24 weeks on site.
Who deals with the council for a project in Letchworth Garden City?
We do. We prepare the drawings, submit planning or permitted development paperwork if needed, and arrange building control inspections.
Other towns nearby
- Bungalow and upward extensions in Hitchin
- Bungalow and upward extensions in Stevenage
- Bungalow and upward extensions in Luton
- Bungalow and upward extensions in Welwyn Garden City
Learn more about bungalow and upward extensions, or see every project we cover in Letchworth Garden City.

