Conservatory replacement extensions across Letchworth Garden City
Planning a conservatory replacement in Letchworth Garden City? We survey the house, work out the planning route, draw the design and build it, so you deal with one team from the first visit to the completion certificate.
- Guide price in Letchworth Garden CityFrom £21,000 inc VAT
- PlanningOften permitted development (3–4 m), or prior approval up to 6–8 m
- Build time8–14 weeks on site
- Postcode districtsSG6

Working in Letchworth Garden City
Our survey diary covers Letchworth Garden City, including SG6. Neighbouring towns we cover include Hitchin (3 miles), Stevenage (5 miles), Welwyn Garden City (12 miles), Harpenden (13 miles).
For homes towards Bedfordshire, Luton is around 11 miles away. Across the East of England many houses sit on generous plots, and single-storey and wraparound extensions are a natural fit.
Do I need planning permission in Letchworth Garden City?
In England a single-storey rear extension can usually go up to 3 m beyond the original rear wall of a semi-detached or terraced house, or 4 m on a detached house, without a planning application, provided it is no more than 4 m high, keeps eaves to 3 m within 2 m of a boundary and, with other buildings, covers no more than half the land around the original house. The larger home extension prior approval scheme raises those depths to 6 m and 8 m, with neighbours notified and a 42-day decision.
In a conservation area, national park, National Landscape, the Broads or a World Heritage Site the permitted development limits are tighter (no side or two-storey extensions without an application). Listed homes need listed building consent, and if permitted development rights have been removed, any extension needs an application.
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).
What should I budget for a conservatory replacement in Letchworth Garden City?
Prices below are for Letchworth Garden City, using the East of England factor of ×1.06. They are guide ranges including VAT for the build only, not a quote.
Typical rates in Letchworth Garden City: £1,960 to £3,710 per m² including VAT, depending on specification.
| Size | Essential | Standard | Premium |
|---|---|---|---|
| 3 m × 3.3 m 10 m² | £21,000 – £25,500 | £22,500 – £29,500 | £29,000 – £37,500 |
| 3.5 m × 4 m 14 m² | £27,000 – £33,000 | £31,500 – £41,000 | £40,500 – £52,000 |
| 4 m × 5 m 20 m² | £39,000 – £47,000 | £45,500 – £58,500 | £58,000 – £74,500 |
Includes removal of the old conservatory. Reusing existing foundations is only possible after investigation.
Want a range for your exact size? The guide-price tool takes about a minute.
Included in a typical project
- Removal and disposal of the old conservatory
- Opening widened into the house if wanted
- New or upgraded foundations
- Glazing and doors to suit the new room
- Insulated walls and roof to current regulations
From first visit to completion
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
We draw the design, agree it with you and handle planning or permitted development checks and building regulations.
Fixed written price
You receive a written, itemised price and programme. Nothing starts until you are happy with it.
Build and sign-off
The build is managed from start to finish, inspected at each stage and signed off on completion.
Conservatory replacement questions answered
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.
Will my neighbours in Letchworth Garden City be involved?
If a planning application or prior approval is needed, the council notifies neighbours. If the work is on or near a shared boundary, party wall notices may also be needed.
Is it worth replacing a conservatory with an extension?
If the conservatory is unusable for much of the year, usually yes. A solid extension gives a heated room that counts as proper living space. Our guide range is about £1,960 to £3,710 per m² including VAT, including removal.
Does replacing a conservatory need planning permission?
A solid replacement is treated as a new extension, so it must meet the permitted development limits or get planning permission, and it always needs building regulations approval.
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.