Bedroom extensions in Letchworth Garden City: design, approvals and build
Letchworth Garden City homeowners can use us for the whole bedroom extension project: survey, design, planning or permitted development checks, building regulations and the build itself.
- Guide price in Letchworth Garden CityFrom £27,500 inc VAT
- PlanningUsually a householder application
- Build time14–22 weeks on site
- Postcode districtsSG6
Covering Letchworth Garden City
We cover Letchworth Garden City and the postcode districts SG6. The same team covers Hitchin (3 miles), Stevenage (5 miles), Welwyn Garden City (12 miles), Harpenden (13 miles), all within easy reach.
Across the East of England many houses sit on generous plots, and single-storey and wraparound extensions are a natural fit.
When a bedroom extension makes sense
- Multi-generational households
- Growing families
- Homeowners who want an en-suite master bedroom
Planning and approvals in Letchworth Garden City
In England a two-storey rear extension is permitted development only if it projects no more than 3 m from the original rear wall, sits at least 7 m from the rear boundary, matches the roof pitch and uses obscure, non-opening side windows upstairs. Most two-storey extensions therefore go through a householder planning application, which costs £548 from 1 April 2026 and normally takes about 8 weeks.
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.
Applications are decided by the local planning authority (your district, borough or unitary council).
How much does a bedroom extension cost 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: £1,700 to £3,390 per m² including VAT, depending on specification.
| Size | Essential | Standard | Premium |
|---|---|---|---|
| One bedroom 12 m² | £27,500 – £34,000 | £27,500 – £36,000 | £30,500 – £41,000 |
| Bedroom and en-suite 18 m² | £30,500 – £37,500 | £36,000 – £47,000 | £45,500 – £61,500 |
| Two rooms 30 m² | £50,500 – £62,500 | £60,000 – £78,000 | £76,000 – £102,000 |
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
First, a site visit: we look at the house, garden, access and drains and listen to what you need.
Design and approvals
We draw the design, agree it with you and handle planning or permitted development checks and building regulations.
Fixed written price
We confirm the build price in writing, based on the approved drawings and the finishes you have chosen.
Build and sign-off
We build it with one project manager, book the building control inspections and hand over the completion certificate.
Common questions in Letchworth Garden City
Do you cover all of Letchworth Garden City?
Yes. We cover Letchworth Garden City and the surrounding parts of Hertfordshire. Site visits are free and there is no obligation.
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.
How long does a bedroom extension take to build in Letchworth Garden City?
On site, typically 14 to 22 weeks once approvals are in place. Before that, allow 8–14 weeks design and approvals.
Can I add a ground-floor bedroom for a relative?
Yes. A ground-floor bedroom with an accessible shower room is a common request. If it will be lived in as a self-contained home, planning treats it differently, so tell us how it will be used.
Will a new bedroom need planning permission?
Upstairs additions usually do. Ground-floor rooms may fall within permitted development, depending on size and position.
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.