Wraparound extensions in Letchworth Garden City: design, approvals and build
Thinking about a wraparound extension for your Letchworth Garden City home? Start with a free site visit: we measure up, check what the council will allow and give you honest guide figures on the day.
- Guide price in Letchworth Garden CityFrom £38,000 inc VAT
- PlanningUsually a householder application
- Build time14–20 weeks on site
- Postcode districtsSG6
Planning rules that apply in Letchworth Garden City
In England a wraparound extension is assessed as both a side and a rear extension, and the combination usually falls outside permitted development, so most need a householder planning application (£548 from 1 April 2026).
Before any drawing is finalised we check whether the house is listed, in a conservation area or subject to an Article 4 direction.
Building over or within 3 m of a public sewer needs the water company's consent, usually through a build-over agreement, before the foundations go in.
Building regulations approval is separate from planning. In England you can use the council's building control team or a registered building control approver; a full plans application gets the drawings checked before work starts, and the inspector signs the work off with a completion certificate.
Applications are decided by the local planning authority (your district, borough or unitary council).
Included in a typical project
- Roof with glazing along the side return
- Structural design for the corner and openings
- Full internal finish or kitchen-ready shell
- Foundations, drainage and any manhole relocation
Extensions in and around Letchworth Garden City
Our survey diary covers Letchworth Garden City, including SG6. Nearby, we also take on projects in Hitchin (3 miles), Stevenage (5 miles), Welwyn Garden City (12 miles), Harpenden (13 miles).
Across the East of England many houses sit on generous plots, and single-storey and wraparound extensions are a natural fit.
What should I budget for a wraparound extension in Letchworth Garden City?
For Letchworth Garden City we adjust our national guide rates by ×1.06, the factor we use for East of England. Figures include VAT; your written quote after the survey replaces them.
Typical rates in Letchworth Garden City: £2,120 to £3,920 per m² including VAT, depending on specification.
| Size | Essential | Standard | Premium |
|---|---|---|---|
| Compact L-shape 18 m² | £38,000 – £46,000 | £43,500 – £55,500 | £55,000 – £71,000 |
| Medium L-shape 25 m² | £53,000 – £64,000 | £60,500 – £77,000 | £76,500 – £98,500 |
| Large L-shape 32 m² | £67,500 – £81,500 | £78,000 – £98,500 | £98,000 – £126,000 |
For a figure based on your own dimensions, use our guide-price tool.
How the project works
Site visits are free and there is no obligation. Where drawings are needed, the design stage is priced in writing before it starts.
Free site visit
A designer visits, takes measurements and photos, and discusses layouts, budget and timing with you.
Design and approvals
Drawings are prepared and agreed with you, then submitted for the right planning route and building regulations approval.
Fixed written price
The price is fixed in writing once the design is settled, with a clear programme and payment stages.
Build and sign-off
Work is carried out to the agreed programme, inspected by building control and signed off at the end.
Questions people ask about wraparound extensions
How long does a wraparound extension take to build in Letchworth Garden City?
On site, typically 14 to 20 weeks once approvals are in place. Before that, allow 8–16 weeks design and approvals.
Do I need building regulations approval in Letchworth Garden City?
Yes. Almost every extension needs it, whatever the planning route. We prepare the drawings and book the inspections.
Can I see a price before committing to anything?
Yes. The guide prices on this page are adjusted for Letchworth Garden City, and the guide-price tool gives a range for your own size. After the survey you get a written price before anything is agreed.
Is a wraparound better than a side return alone?
It adds far more space, but costs more and needs planning permission more often. Our comparison guide sets the two side by side.
How much does a wraparound extension cost?
Our guide range is about £2,120 to £3,920 per m² including VAT. A 25 m² standard-spec wraparound typically lands around £60,500 to £77,000 in Letchworth Garden City before design and council fees.
Book a free site visit in Letchworth Garden City
We will measure up, check the planning position and give you honest guide figures.
- Free, no-obligation site visit
- Planning route checked before you spend on drawings
- Written price once the design is agreed
- Building control sign-off at the end
Prefer to talk? Call 0800 088 6341 or .
Book a free site visit
Tell us a little about the project and we will arrange a time.