King's Lynn house extensions
Planning an extension in King's Lynn? Compare extension types, see guide prices adjusted for King's Lynn and book a free site visit.
- Postcode districtsPE30, PE34
- Price regionEast of England (×1.06)
- Planning rulesEngland
- Site visitFree, no obligation
What works best for King's Lynn houses?
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.
The types we would usually look at first for a home in King's Lynn are double-storey extensions, bungalow extensions and single-storey rear extensions, depending on the garden and how the house is laid out.
Where we work near King's Lynn
Across PE30, PE34, we can visit, measure and advise. Nearby, we also take on projects in Dereham (23 miles), Thetford (28 miles), Wymondham (32 miles), Norwich (39 miles), Cromer (40 miles). For homes towards Cambridgeshire, Wisbech is around 12 miles away.
Guide prices for King's Lynn
Every figure below is a guide for King's Lynn, adjusted for East of England build costs (×1.06) and including VAT. Design and council fees are shown separately on each page.
| Extension type | Example size | Standard spec (inc VAT) |
|---|---|---|
| Side return extensions | 11 m² | £27,500 – £35,000 |
| Orangery extensions | 16 m² | £47,000 – £59,500 |
| Single-storey rear extensions | 20 m² | £43,000 – £55,500 |
| Wraparound extensions | 25 m² | £60,500 – £77,000 |
| Kitchen extensions | 20 m² | £44,500 – £56,500 |
Do extensions in King's Lynn need planning permission?
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 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.
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.
If the work involves a shared wall, building on the boundary, or digging foundations within 3 m (sometimes 6 m) of a neighbour's building, the Party Wall etc. Act 1996 applies and notice must be served before work starts: two months for work to a party wall, one month for new walls on the boundary and for excavations.
Applications are decided by the local planning authority (your district, borough or unitary council).
Every extension type in King's Lynn
- Glass box extensions · from £31,500
- Side extensions · from £23,000
- Pitched roof extensions · from £23,500
- Orangery extensions · from £31,500
- Side return extensions · from £19,000
- Timber frame extensions · from £22,000
- Bungalow extensions · from £27,500
- Flat roof extensions · from £22,000
- Annexe extensions · from £58,000
- Kitchen extensions · from £28,500
- Porch extensions · from £4,200
- Conservatory replacement extensions · from £21,000
- Single-storey rear extensions · from £22,000
- Double-storey extensions · from £40,000
- Extensions over a garage · from £25,000
- Bedroom extensions · from £27,500
- Utility and boot room extensions · from £14,500
- Home office extensions · from £16,500
- Building regulations for extensions · from £950
- Extension plans and drawings · from £1,250
- Wraparound extensions · from £38,000
- Planning permission for extensions · from £350
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
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
We confirm the build price in writing, based on the approved drawings and the finishes you have chosen.
Build and sign-off
Our team builds the extension, keeps you updated weekly and finishes with building control sign-off.
Questions about extensions in King's Lynn
How much does an extension cost in King's Lynn?
Using our East of England factor (×1.06), a standard-spec single-storey extension of 20 m² is a guide £43,000 to £55,500 including VAT, and a 32 m² two-storey extension £61,000 to £80,000. Your written price follows the survey.
Do you handle building regulations?
Yes. We prepare the drawings and calculations, submit them and book inspections, ending with a completion certificate.
Can I get a price before anyone visits?
Yes. This page shows guide prices adjusted for King's Lynn, and the guide-price tool gives a range for your own size and finish in about a minute.
Do I need planning permission for an extension in King's Lynn?
Not always. It depends on the size, position and your property's history. Many single-storey rear extensions in England are permitted development or can use prior approval.
Who do I contract with?
Your contract is with S&K Property Investments and Improvement Ltd, which designs and manages the project and the build teams who carry it out.
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.