- Postcode district
- BT1
- Survey
- Free, area covered by arrangement
- Typical lead time
- Typically 6–8 weeks for slimline systems after check survey sign-off
- Guide price
- From £5,095 inc VAT
- Nearby
- Newtownabbey, Holywood, Lisburn
- Building rules
- Northern Ireland
What sliding doors for extensions offer homes in Belfast
Before you settle on a door type, it helps to know what sliding doors for extensions do well and what to check before you order.
Planning an extension in Belfast? Send us the drawings before the steel is ordered, so the beam above the doors can be designed with the door in mind.
If your Belfast builder is about to pour the screed, confirm the finished floor level for the threshold first, because it is very hard to change afterwards.
- Garden rooms benefit from the same approach, with a door sized to the frame and a header designed to carry the roof without pressing down on the door.
- Being involved at drawing stage means the opening is formed to suit the door, rather than the door being compromised to suit an opening built a few centimetres out.
- Slimline aluminium systems with interlocks typically around 20–25 mm maximise the glass in a new rear wall, keeping the view as open as possible.
Daylight in Belfast and what it means for your glass
At the latitude of Belfast, the midday sun climbs to about 59° in late June but only about 12° in late December, when daylight lasts around 7 h 15 min against 17 h 17 min in midsummer. A south-facing sliding door for an extension lets that low winter sun deep into the room; on a west or south elevation, solar-control glass keeps summer afternoons comfortable.
Guide prices for sliding doors for extensions in Belfast
Guide prices are the same across County Antrim. They cover the door supplied and fitted into a prepared opening, including VAT, with options itemised in your quote.
| Overall width | Typical panels | Guide price (fitted, inc VAT) |
|---|---|---|
| 2.1 m | 2 panels | £5,495–£6,795 |
| 2.4 m | 2 panels | £5,995–£7,295 |
| 4.0 m | 3 panels | £8,395–£10,195 |
See every size on the sliding doors for extensions page or try the guide price tool.
What happens when you order sliding doors for extensions in Belfast?
Here is the usual sequence in Belfast: guide price, free survey, written quote, any building work, then manufacture (typically 6–8 weeks for slimline systems after check survey sign-off). Fitting typically takes 1–2 days, scheduled to the build programme. Nearby, we also survey in Newtownabbey, Holywood and Lisburn. Belfast is in an area we cover by arrangement: the survey is still free, and survey dates, delivery and any travel cost for delivery and fitting are confirmed in your quote before you order.
Do you need approval in Belfast?
In Northern Ireland, an extension needs building control approval from your district council, which covers the doors and glazing. Work in Northern Ireland is by arrangement.
Which options matter for sliding doors for extensions?
- Two-panel slimline. One sliding and one fixed panel, suiting openings up to around 3.6 m depending on the system.
- Flush threshold. A level floor from inside to out, with a drainage channel set into the patio.
- Corner opening. Sliding panels meeting at a corner with no post, for extensions open on two sides.
Questions about sliding doors for extensions in Belfast
How soon can you survey in Belfast?
Survey dates in the BT1 district are arranged individually when we reply to your enquiry. After you approve the written quote, manufacture is typically 6–8 weeks for slimline systems after check survey sign-off.
Can you work with my builder and architect?
Yes, working with your builder, architect and structural engineer is the normal way we approach extension doors. We can provide technical details, opening sizes, threshold requirements and fixing information, and attend site for the check survey. Your builder forms the opening and prepares the floor, and our installers fit the doors to the agreed programme.
How much do sliding doors for an extension cost?
Slimline sliding doors for an extension have a guide price of £7,795–£9,495 for a 3.6 m opening and £9,595–£11,695 for a 4.8 m opening, fitted, inc VAT at standard 2.1 m height. Taller doors, extra panels, special glass and flush thresholds move the price. Your written quote after the check survey fixes it.
What structural opening size should my builder leave for sliding doors?
Your builder should leave the structural opening size we give in writing for your chosen door, which is the frame size plus a small fitting tolerance on each side and at the head. The exact figure depends on the system and the threshold detail. We confirm it from your drawings early, then check the built opening before the door is made.