Timber frame extensions for homes in County Down
Our design and build teams take on timber frame extensions in County Down, from the first measured survey through planning and building control to the finished room.
- Guide priceFrom £18,000 inc VAT
- PlanningNI permitted development (rear 3–4 m) or planning
- Towns covered5
- Site visitFree, no obligation

Towns in County Down
How much does a timber frame extension cost in County Down?
For County Down we adjust our national guide rates by ×0.86, the factor we use for Northern Ireland. Figures include VAT; your written quote after the survey replaces them.
Typical rates in County Down: £1,500 to £2,920 per m² including VAT, depending on specification.
| Size | Essential | Standard | Premium |
|---|---|---|---|
| 3 m × 4 m 12 m² | £18,000 – £22,000 | £21,000 – £27,500 | £26,500 – £35,500 |
| 4 m × 5 m 20 m² | £30,000 – £36,500 | £35,000 – £46,000 | £44,500 – £58,500 |
| 5 m × 6 m 30 m² | £45,000 – £54,500 | £52,500 – £68,500 | £67,000 – £88,000 |
Try the guide-price tool to see a range for your own size and finish.
Do I need planning permission in County Down?
In Northern Ireland the Planning (General Permitted Development) Order 2015 lets some single-storey rear extensions go ahead without planning permission, up to 3 m on a semi-detached or terraced house and 4 m on a detached house, within height and boundary limits. Larger, side and two-storey extensions normally need planning permission from the council, and building control approval is separate.
Before any drawing is finalised we check whether the house is listed, in a conservation area or subject to an Article 4 direction.
Building close to a public sewer needs the agreement of NI Water, which we check during design.
Applications are decided by your council, which handles local planning in Northern Ireland.
When a timber frame extension makes sense
- Sites where weight or speed matters
- Contemporary designs with timber or board cladding
- Homeowners who want strong energy performance
Working in County Down
Towns we cover in County Down include Bangor, County Down, Newtownards, Newry, Banbridge, Downpatrick. Northern Ireland's housing ranges from city terraces to large numbers of detached houses and bungalows on rural plots, many in render, where single-storey extensions fit easily.
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
A designer visits, takes measurements and photos, and discusses layouts, budget and timing with you.
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
The build is managed from start to finish, inspected at each stage and signed off on completion.
Timber frame extension questions answered
Will my neighbours in County Down be involved?
If a planning application is needed, the council notifies neighbours. Where work is close to a shared boundary, we agree access and protection with them in writing.
Can I see a price before committing to anything?
Yes. The guide prices on this page are adjusted for County Down, and the guide-price tool gives a range for your own size. After the survey you get a written price before anything is agreed.
Do I need building regulations approval in County Down?
Yes. Almost every extension needs it, whatever the planning route. We prepare the drawings and book the inspections.
Is timber frame cheaper than brick?
It is similar overall. The frame can save time on site, but the cladding choice has a big effect on cost. Our guide range is about £1,500 to £2,920 per m² including VAT.
Does a timber frame extension need planning permission?
The same planning rules apply as for any extension. If the cladding looks different from the house, permitted development’s matching-materials condition may mean an application is needed.
Book a free site visit in County Down
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.