Glass box extensions across County Antrim
A glass extension in County Antrim 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 £25,500 inc VAT
- PlanningNI permitted development (rear 3–4 m) or planning
- Towns covered8
- Site visitFree, no obligation
Towns in County Antrim
Included in a typical project
- Design with specialist glazing input
- Drainage details for frameless roofs
- Steel or glass beams and slim-frame glazing
- Solar-control and low-energy glass specification
- Planning drawings that show the glass detail
How much does a glass extension cost in County Antrim?
These guide figures apply our Northern Ireland adjustment (×0.86) to national rates. They include VAT at 20% and cover the build itself; design and council fees are listed separately.
Typical rates in County Antrim: £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 |
Try the guide-price tool to see a range for your own size and finish.
Planning rules that apply in County Antrim
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.
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.
Covering County Antrim
Towns we cover in County Antrim include Belfast, Lisburn, Newtownabbey, Castlereagh, Carrickfergus, Ballymena, Antrim, Larne. In Northern Ireland, extension projects follow the NI planning rules and council building control, which we account for from the first survey.
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 Antrim home, measure up, talk through what you want and check the planning position.
Design and approvals
We draw the design, agree it with you and handle planning or permitted development checks and building regulations.
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.
Glass extension questions answered
How long does a glass extension take to build in County Antrim?
On site, typically 10 to 16 weeks once approvals are in place. Before that, allow 8–14 weeks design and approvals.
Who do I contract with for a glass extension in County Antrim?
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.
Will my neighbours in County Antrim 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.
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.
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 Antrim.
Book a free site visit in County Antrim
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.