- Postcode district
- BT47
- Survey
- Free, area covered by arrangement
- Typical lead time
- Typically 4–6 weeks for the door after the opening is measured; building work scheduled around approvals
- Guide price
- From £6,595 inc VAT
- Nearby
- Strabane, Limavady, Dungiven
- Building rules
- Northern Ireland
New and widened openings for sliding doors in Derry/Londonderry: what to know
Most homeowners choosing sliding doors for new openings want the same things: more light, a clear view and a door that is easy to live with.
Thinking about a wider opening in Derry/Londonderry but unsure of the size? Mark it out on the wall inside and out with tape, then picture the furniture and the view before you decide.
Living in a Derry/Londonderry flat? Structural changes to an external wall almost always need the agreement of the building's owner or the other owners, so speak to them first.
- Making good the reveals and head after the steel goes in leaves a square, plumb opening, which is what a precision-made sliding door needs to run smoothly.
- A structural engineer sizes the steel beam and padstones for the actual loads above, so the opening is designed rather than guessed.
- Structural calculations are included in the guide price, and the Building Regulations application is handled as part of the project, so you are not left coordinating engineers and inspectors.
Sunlight, glass and orientation in Derry/Londonderry
Sun angles matter for big glazed doors. Around Derry/Londonderry, midday sun reaches about 58° in summer and drops to about 12° in winter. That low winter sun is free heat through south-facing glass; high summer sun is easier to shade with a roof overhang, and solar-control glass helps where there is none.
Guide prices for sliding doors for new openings in Derry/Londonderry
Use these guide prices to budget for the whole job in Derry/Londonderry: the door, the steelwork, making good and the engineer's calculations, including VAT. Building Control or warrant fees are charged by the council on top.
| Overall width | Typical panels | Guide price (fitted, inc VAT) |
|---|---|---|
| 1.5 m | 2 panels | £6,595–£7,295 |
| 4.0 m | 3 panels | £10,295–£11,595 |
| 6.0 m | 4 panels | £13,295–£15,095 |
See every size on the sliding doors for new openings page or try the guide price tool.
How fitting works in Derry/Londonderry
A surveyor visits your Derry/Londonderry home to check the wall, the structure above and the floor levels, and talks through glass and finish. Any building work is planned to the engineer's design, the door is made to the finished opening sizes — typically 4–6 weeks for the door after the opening is measured; building work scheduled around approvals — and fitting usually takes 3–5 days of building work, then 1–2 days to fit the door. Derry/Londonderry 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 Derry/Londonderry?
In Northern Ireland, structural alterations need approval from your district council's building control service before work starts. New openings in Northern Ireland are by arrangement.
Which options matter for sliding doors for new openings?
- Concealed steel. Setting the beam so it sits above the ceiling line, giving a cleaner head detail inside.
- Window to door conversion. Cutting down below an existing window to form a door opening to the garden.
- Steel beam with padstones. A beam sized by the engineer to carry the wall, floors and roof above.
Questions about sliding doors for new openings in Derry/Londonderry
How soon can you survey in Derry/Londonderry?
Survey dates in the BT47 district are arranged individually when we reply to your enquiry. After you approve the written quote, manufacture is typically 4–6 weeks for the door after the opening is measured; building work scheduled around approvals.
Why does beam deflection matter for sliding doors?
Beam deflection matters because a sliding door needs a straight, level head to run properly. Every beam bends slightly under load, and if it bends too much the frame can be squeezed, making panels stiff or causing them to bind. Telling the structural engineer that a large sliding door will go underneath allows them to design a stiffer beam.
Do I need a steel beam for sliding doors?
A widened or new opening usually needs a steel beam or a suitable lintel to carry the wall and anything above it, and for wider openings a steel beam is the usual answer. A structural engineer chooses the size and bearing details based on the loads. The beam is placed on padstones at each end to spread its load into the masonry.
Can you turn a window into a sliding door?
Yes, a window opening can usually be extended down to the floor and often widened to take a sliding door. The work involves removing the masonry below the window, forming a new threshold, and fitting a steel beam or lintel if the opening is widened. Drains, air bricks and floor levels outside need checking, and the work needs a Building Regulations application.