Glass box extensions in County Londonderry
Planning a glass extension in County Londonderry? 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 £25,500 inc VAT
- PlanningNI permitted development (rear 3–4 m) or planning
- Towns covered4
- Site visitFree, no obligation
Towns in County Londonderry
What should I budget for a glass extension in County Londonderry?
Prices below are for County Londonderry, using the Northern Ireland factor of ×0.86. They are guide ranges including VAT for the build only, not a quote.
Typical rates in County Londonderry: £2,580 to £4,990 per m² including VAT, depending on specification.
| Size | Essential | Standard | Premium |
|---|---|---|---|
| 2 m × 4 m 8 m² | £25,500 – £31,000 | £25,500 – £32,500 | £29,500 – £40,000 |
| 3 m × 4 m 12 m² | £30,500 – £37,500 | £36,000 – £45,500 | £44,000 – £60,000 |
| 3 m × 6 m 18 m² | £46,000 – £56,000 | £54,000 – £68,500 | £66,500 – £90,000 |
Want a range for your exact size? The guide-price tool takes about a minute.
Extensions in and around County Londonderry
Towns we cover in County Londonderry include Derry/Londonderry, Coleraine, Limavady, Magherafelt. In Northern Ireland, extension projects follow the NI planning rules and council building control, which we account for from the first survey.
Included in a typical project
- Planning drawings that show the glass detail
- Steel or glass beams and slim-frame glazing
- Whole-house energy calculations where needed
- Solar-control and low-energy glass specification
- Drainage details for frameless roofs
Solar gain is the risk. We specify solar-control glass, plan for opening vents or sliding panels, and avoid fully glazed roofs on south-facing extensions unless shading is included.
Planning and approvals in County Londonderry
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.
In a conservation area or area of townscape character the permitted development rights are more limited, listed homes need listed building consent, and if rights have been removed by a condition, any extension needs an application.
In Northern Ireland building control is run by the councils under the Building Regulations (Northern Ireland). We submit full plans or a building notice and book the inspections through to completion.
Applications are decided by your council, which handles local planning in Northern Ireland.
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
We visit your County Londonderry home, measure up, talk through what you want and check the planning position.
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.
Questions people ask about glass extensions
Who do I contract with for a glass extension in County Londonderry?
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 you cover all of County Londonderry?
Yes, across the whole of County Londonderry. Site visits are free and there is no obligation.
Will my neighbours in County Londonderry 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.
How much does a glass extension cost?
Our guide range is about £2,580 to £4,990 per m² including VAT, because structural glass is made to order. A 12 m² standard-spec glass extension is typically £36,000 to £45,500 in County Londonderry.
Are glass extensions cold in winter?
Modern double or triple glazing with warm-edge spacers and underfloor heating keeps them comfortable. They are not as warm as a solid room, and we explain the trade-off honestly.
Book a free site visit in County Londonderry
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.