Home extensions in Falmouth
From a small utility to a two-storey addition, we take on house extensions throughout Falmouth, starting with a free visit and a planning check.
- Postcode districtsTR10, TR11
- Price regionSouth West England (×1.02)
- Planning rulesEngland
- Site visitFree, no obligation
Areas we cover around Falmouth
Across TR10, TR11, we can visit, measure and advise. Neighbouring towns we cover include Truro (8 miles), Redruth (9 miles), Camborne (11 miles), Newquay (18 miles), St Austell (18 miles). Just over the Devon border, Plymouth is about 44 miles away.
Choosing the right extension in Falmouth
South West homes range from terraced streets in the cities to stone cottages and bungalows in the countryside, and conservation areas are common in historic centres.
For many houses here, single-storey rear extensions, annexe extensions or pitched roof extensions gives the most useful space for the budget.
What extensions cost in Falmouth
We publish guide prices so you can budget before anyone visits. For Falmouth they are adjusted by ×1.02, the factor we use across South West England.
| Extension type | Example size | Standard spec (inc VAT) |
|---|---|---|
| Kitchen extensions | 20 m² | £42,500 – £54,500 |
| Conservatory replacement extensions | 14 m² | £30,500 – £39,500 |
| Side return extensions | 11 m² | £26,500 – £34,000 |
| Extensions over a garage | 12 m² | £25,500 – £33,500 |
| Wraparound extensions | 25 m² | £58,500 – £74,000 |
| Single-storey rear extensions | 20 m² | £41,500 – £53,500 |
Approvals for an extension in Falmouth
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).
Choose an extension type
- Orangery extensions · from £30,500
- Extensions over a garage · from £24,000
- Bedroom extensions · from £26,500
- Bungalow extensions · from £26,500
- Flat roof extensions · from £21,000
- Timber frame extensions · from £21,000
- Wraparound extensions · from £36,500
- Home office extensions · from £16,000
- Single-storey rear extensions · from £21,000
- Extension plans and drawings · from £1,200
- Double-storey extensions · from £38,500
- Kitchen extensions · from £27,500
- Side extensions · from £22,000
- Glass box extensions · from £30,500
- Side return extensions · from £18,000
- Utility and boot room extensions · from £14,000
- Pitched roof extensions · from £22,500
- Annexe extensions · from £56,000
- Porch extensions · from £4,050
- Building regulations for extensions · from £900
- Conservatory replacement extensions · from £20,000
- Planning permission for extensions · from £350
Free site visit
We visit your Falmouth 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
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 about extensions in Falmouth
How much does an extension cost in Falmouth?
Using our South West England factor (×1.02), a standard-spec single-storey extension of 20 m² is a guide £41,500 to £53,500 including VAT, and a 32 m² two-storey extension £58,500 to £77,000. Your written price follows the survey.
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.
Will my neighbours need to be told?
If you apply for planning or prior approval the council notifies them, and in England party wall notices may be needed for work near a shared boundary.
Do I need planning permission for an extension in Falmouth?
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.
Can I get a price before anyone visits?
Yes. This page shows guide prices adjusted for Falmouth, and the guide-price tool gives a range for your own size and finish in about a minute.
Book a free site visit in Falmouth
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.