Durham annexe extensions, designed and built
We design and build annexe extensions for houses in Durham, with a written price once the survey and design are done and one point of contact throughout.
- Guide price in DurhamFrom £50,000 inc VAT
- PlanningUsually a householder application
- Build time16–24 weeks on site
- Postcode districtsDH1
Will the council need to approve it?
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).
Working in Durham
Across DH1, we can visit, measure and advise. We also work in nearby Chester-le-Street (6 miles), Stanley (8 miles), Bishop Auckland (9 miles), Peterlee (10 miles).
Across the North East, houses often have rear yards or modest gardens, so compact, well-lit single-storey extensions make the biggest difference.
Annexe extension prices in Durham
Prices below are for Durham, using the North East England factor of ×0.91. They are guide ranges including VAT for the build only, not a quote.
Typical rates in 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.
What is included
- Separate or shared heating and hot water
- Design for accessibility: level thresholds, wider doors, walk-in shower
- Planning application describing ancillary use
- Fire separation and alarms to building regulations
- Kitchenette, shower room and bedroom finish
Our process, step by step
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
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
Our team builds the extension, keeps you updated weekly and finishes with building control sign-off.
Common questions in Durham
How long does an annexe extension take to build in Durham?
On site, typically 16 to 24 weeks once approvals are in place. Before that, allow 10–16 weeks design and approvals.
Who do I contract with for an annexe extension in 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.
Do I need building regulations approval in Durham?
Yes. Almost every extension needs it, whatever the planning route. We prepare the drawings and book the inspections.
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.
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 Durham.
Book a free site visit in 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.