Single-storey rear extensions in King's Lynn: design, approvals and build
If you live in King's Lynn and want more space without moving, a single-storey extension is one of the most practical ways to get it. We handle the drawings, approvals and the build.
- Guide price in King's LynnFrom £22,000 inc VAT
- PlanningOften permitted development (3–4 m), or prior approval up to 6–8 m
- Build time10–16 weeks on site
- Postcode districtsPE30, PE34
Included in a typical project
- Planning route checked and the right approval obtained
- Flat or pitched roof, rooflights or lantern
- Doors, windows, insulation, plastering and first fix to finish
- Building regulations drawings and structural calculations
- Measured survey and design
Single-storey extension prices in King's Lynn
Prices below are for King's Lynn, 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 King's Lynn: £1,860 to £3,600 per m² including VAT, depending on specification.
| Size | Essential | Standard | Premium |
|---|---|---|---|
| 3 m × 4 m 12 m² | £22,000 – £26,500 | £26,000 – £33,500 | £33,000 – £43,500 |
| 4 m × 5 m 20 m² | £37,000 – £43,500 | £43,000 – £55,500 | £55,000 – £72,500 |
| 5 m × 6 m 30 m² | £55,500 – £65,500 | £65,000 – £83,000 | £82,500 – £108,500 |
Try the guide-price tool to see a range for your own size and finish.
Planning and approvals in King's Lynn
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 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).
Covering King's Lynn
Our survey diary covers King's Lynn, including PE30, PE34. The same team covers Dereham (23 miles), Thetford (28 miles), Wymondham (32 miles), Norwich (39 miles), all within easy reach.
For homes towards Cambridgeshire, Wisbech is around 12 miles away. The East of England mixes market-town terraces, inter-war semis and modern estates. Clay soils are common in parts of the region, which can affect foundation design.
What happens next
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
We visit your King's Lynn home, measure up, talk through what you want and check the planning position.
Design and approvals
Once the layout is agreed, we deal with the council: planning permission or written confirmation that none is needed, plus building control.
Fixed written price
You receive a written, itemised price and programme. Nothing starts until you are happy with it.
Build and sign-off
Work is carried out to the agreed programme, inspected by building control and signed off at the end.
Common questions in King's Lynn
Do you cover all of King's Lynn?
Yes. We cover King's Lynn and the surrounding parts of Norfolk. Site visits are free and there is no obligation.
How long does a single-storey extension take to build in King's Lynn?
On site, typically 10 to 16 weeks once approvals are in place. Before that, allow 4–12 weeks design and approvals.
Do I need building regulations approval in King's Lynn?
Yes. Almost every extension needs it, whatever the planning route. We prepare the drawings and book the inspections.
How much does a single-storey extension cost per square metre?
Our guide range is about £1,860 to £3,600 per m² including VAT, depending on specification. A standard-spec 4 m × 5 m room usually lands at £43,000 to £55,500 in King's Lynn, plus design and council fees.
Flat roof or pitched roof?
Flat roofs give more headroom inside and suit lanterns and rooflights; pitched roofs can blend better with older houses. Both meet building regulations when built properly. See our flat roof and pitched roof pages for the details.
Book a free site visit in King's Lynn
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.