Annexe extensions for homes in Camborne
Camborne homeowners can use us for the whole annexe extension project: survey, design, planning or permitted development checks, building regulations and the build itself.
- Guide price in CamborneFrom £56,000 inc VAT
- PlanningUsually a householder application
- Build time16–24 weeks on site
- Postcode districtsTR14

What should I budget for an annexe extension in Camborne?
Labour and material costs vary across the UK, so for Camborne we use our South West England factor (×1.02). The ranges include VAT and exclude design, structural and council fees.
Typical rates in Camborne: £2,040 to £3,880 per m² including VAT, depending on specification.
| Size | Essential | Standard | Premium |
|---|---|---|---|
| Studio annexe 25 m² | £56,000 – £70,500 | £61,000 – £76,500 | £76,500 – £97,000 |
| One-bedroom annexe 35 m² | £71,000 – £89,500 | £85,500 – £107,500 | £107,000 – £136,000 |
| Larger annexe 45 m² | £91,500 – £115,000 | £110,000 – £138,000 | £137,500 – £174,500 |
Want a range for your exact size? The guide-price tool takes about a minute.
What we take care of
- Kitchenette, shower room and bedroom finish
- Planning application describing ancillary use
- Fire separation and alarms to building regulations
- Separate or shared heating and hot water
- Design for accessibility: level thresholds, wider doors, walk-in shower
Accessibility is cheaper to design in than to retrofit. Level access, a 900 mm door width, a level-access shower and space to turn a wheelchair can all be planned into the footprint for little extra cost.
Extensions in and around Camborne
Our survey diary covers Camborne, including TR14. Nearby, we also take on projects in Redruth (4 miles), Falmouth (11 miles), Truro (11 miles), Penzance (12 miles).
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.
Planning rules that apply in Camborne
In England an annexe that stays part of the household and connects to the house is assessed as an extension, but its size usually takes it beyond permitted development, so a householder application describing the ancillary use is the normal route.
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).
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
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
With the design and specification agreed, you get a fixed written price and a start date.
Build and sign-off
Our team builds the extension, keeps you updated weekly and finishes with building control sign-off.
Annexe extension questions answered
Will my neighbours in Camborne 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.
Can I see a price before committing to anything?
Yes. The guide prices on this page are adjusted for Camborne, and the guide-price tool gives a range for your own size. After the survey you get a written price before anything is agreed.
Who do I contract with for an annexe extension in Camborne?
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.
How much does an annexe extension cost?
Our guide range is about £2,040 to £3,880 per m² including VAT. A one-bedroom annexe of about 35 m² is typically £85,500 to £107,500 at standard spec in Camborne.
Will an annexe affect council tax?
It can. Some annexes are assessed separately for council tax, with discounts or exemptions in some cases when occupied by a relative. Check with the Valuation Office Agency (England and Wales), your local assessor (Scotland) or Land & Property Services (Northern Ireland).
Book a free site visit in Camborne
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.