Pitched roof extensions in County Down
Planning a pitched roof extension in County Down? We survey the house, work out the planning route, draw the design and build it, so you deal with one team from the first visit to the completion certificate.
- Guide priceFrom £19,000 inc VAT
- PlanningNI permitted development (rear 3–4 m) or planning
- Towns covered5
- Site visitFree, no obligation

Towns in County Down
What we take care of
- Vaulted ceilings or flat ceilings with storage above
- Insulation to current building regulations
- Roof design matched to the existing pitch and tiles
- Roof windows positioned for light and ventilation
- Lead or proprietary flashings to the main wall
Extensions in and around 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.
Planning and approvals 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.
The planning position for a specific County Down address depends on its history and any designations, which is why we check it at the first visit.
Building close to a public sewer needs the agreement of NI Water, which we check during design.
Northern Ireland has no Party Wall Act. Where work is on or close to a shared boundary, we agree access and protection with your neighbour in writing before work starts.
Applications are decided by your council, which handles local planning in Northern Ireland.
How much does a pitched roof 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: £1,590 to £3,010 per m² including VAT, depending on specification.
| Size | Essential | Standard | Premium |
|---|---|---|---|
| 3 m × 4 m 12 m² | £19,000 – £22,500 | £22,000 – £28,500 | £28,000 – £36,500 |
| 4 m × 5 m 20 m² | £31,500 – £37,000 | £36,500 – £47,500 | £47,000 – £60,500 |
| 5 m × 6 m 30 m² | £47,500 – £55,500 | £55,000 – £71,000 | £70,500 – £90,500 |
Want a range for your exact size? The guide-price tool takes about a minute.
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
First, a site visit: we look at the house, garden, access and drains and listen to what you need.
Design and approvals
We produce the drawings and structural design, and manage the approvals so they are in place before work starts.
Fixed written price
We confirm the build price in writing, based on the approved drawings and the finishes you have chosen.
Build and sign-off
Our team builds the extension, keeps you updated weekly and finishes with building control sign-off.
Common questions in County Down
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.
Do you cover all of County Down?
Yes, across the whole of County Down. Site visits are free and there is no obligation.
Who do I contract with for a pitched roof extension in County Down?
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.
Is a pitched roof better than a flat roof?
Neither is better in all cases. Pitched roofs blend with traditional houses and shed water quickly; flat roofs give more headroom and suit modern designs and lanterns.
Can I have a vaulted ceiling?
Yes. A vaulted ceiling with roof windows is one of the main reasons to choose a pitched roof. It needs insulation between and under the rafters to meet the building regulations.
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.