Annexe extensions for homes in County Durham
A annexe extension in County Durham starts with the right design and the right approval route. We take care of both, then build it with our own project management.
- Guide priceFrom £50,000 inc VAT
- PlanningUsually a householder application
- Towns covered14
- Site visitFree, no obligation
Towns in County Durham
What is included
- Fire separation and alarms to building regulations
- Design for accessibility: level thresholds, wider doors, walk-in shower
- Planning application describing ancillary use
- Kitchenette, shower room and bedroom finish
What should I budget for an annexe extension in County Durham?
Labour and material costs vary across the UK, so for County Durham we use our North East England factor (×0.91). The ranges include VAT and exclude design, structural and council fees.
Typical rates in County Durham: £1,820 to £3,460 per m² including VAT, depending on specification.
| Size | Essential | Standard | Premium |
|---|---|---|---|
| Studio annexe 25 m² | £50,000 – £63,000 | £54,500 – £68,500 | £68,000 – £86,500 |
| One-bedroom annexe 35 m² | £63,500 – £80,000 | £76,000 – £96,000 | £95,500 – £121,500 |
| Larger annexe 45 m² | £81,500 – £102,500 | £98,000 – £123,000 | £122,500 – £156,000 |
Try the guide-price tool to see a range for your own size and finish.
Do I need planning permission in County Durham?
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.
Homes in conservation areas, national parks, National Landscapes (formerly AONBs), the Broads and World Heritage Sites have tighter rules, so we always check the property's status and planning history before design starts.
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.
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 County Durham
Towns we cover in County Durham include Darlington, Hartlepool, Stockton-on-Tees, Durham, Chester-le-Street, Billingham, Stanley, Consett. Across the North East, houses often have rear yards or modest gardens, so compact, well-lit single-storey extensions make the biggest difference.
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
It starts with a visit to your house to measure, check access and talk through ideas and budget.
Design and approvals
Drawings are prepared and agreed with you, then submitted for the right planning route and building regulations approval.
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
We build it with one project manager, book the building control inspections and hand over the completion certificate.
Questions people ask about annexe extensions
Who do I contract with for an annexe extension in County Durham?
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 long does an annexe extension take to build in County Durham?
On site, typically 16 to 24 weeks once approvals are in place. Before that, allow 10–16 weeks design and approvals.
Do you cover all of County Durham?
Yes, across the whole of County Durham. Site visits are free and there is no obligation.
How much does an annexe extension cost?
Our guide range is about £1,820 to £3,460 per m² including VAT. A one-bedroom annexe of about 35 m² is typically £76,000 to £96,000 at standard spec in County Durham.
Can the annexe have its own front door?
Yes, many do, but it should still connect to the main house to stay clearly part of it.
Book a free site visit in County Durham
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.