Doors
Bi-fold doors
Aluminium bi-fold doors cost roughly £3,000 to £7,500 supplied and fitted, driven mainly by the width of the opening and the number of panels. They concertina back against one or both sides, opening almost the whole aperture, which is their advantage over sliding doors.
Bi-folds open an opening almost completely. That is the thing they do better than anything else, and whether it is worth the cost depends on how much you will actually use them that way.
Indicative guide, not a quote
per door, supplied and fitted
£3,000 – £7,500
These figures come from published industry price guides, not official statistics, and several of those sources are installers or comparison sites with a commercial interest. They are a starting point for a conversation, not a quote. Your installer sets the actual price after measuring.
MyJobQuote door installation cost guides · checked 2026-10-09
Panels, widths and the traffic door
Bi-folds are priced by opening width and panel count. A three-panel set up to about three metres sits at the lower end; five panels across five metres or more sits at the top.
Most sets include a traffic door: a single leaf that opens on its own like a normal door, so you are not folding the whole run back to let the cat out. Without one, a bi-fold is irritating in daily use, so confirm it is in the specification.
Bi-fold or sliding
A bi-fold opens the full width but leaves a stack of folded panels at the side, and has a frame line at every panel when closed. A sliding door never opens more than half the aperture, but has far fewer frame lines and a much bigger uninterrupted pane when shut.
The honest question is how much of the year the doors are actually open. If the answer is a few weeks, the view when closed may matter more than the opening.
Thresholds, drainage and the structural opening
A flush threshold looks far better and removes a trip hazard, but needs drainage designed into it. A rebated threshold is more weathertight and cheaper, at the cost of a visible upstand.
If you are widening an existing opening, you need a structural opening with an adequate lintel, and that is a separate cost from the doors. Price the building work and the doors together rather than being surprised by the second one.
Bi-fold doors: common questions
- Are bi-fold doors secure?
- Good aluminium sets use multi-point locking on the traffic door and shootbolts on the folding leaves, and can be PAS 24 tested. As ever, confirm the test and the cylinder rather than assuming.
- Do bi-fold doors leak?
- A correctly specified and installed set does not. Water ingress is nearly always a threshold or drainage detail, which is why flush thresholds need designing rather than just ordering.
- How much does a 4m bi-fold cost?
- A four-metre aluminium set typically falls somewhere in the middle of the £3,000 to £7,500 range, before any structural work to the opening. Specification and glass choice move it within that band.
Other doors
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Front doors
£900 – £2,350 fitted
A new front door costs £700 to £2,800 fitted. Composite, uPVC, aluminium and timber compared, and why the lock matters more than the door.
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Composite doors
£900 – £2,350 fitted
Composite doors cost £900 to £2,350 fitted. Solid timber core versus foam, what thickness to ask for, and the security specification worth insisting on.
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uPVC doors
£700 – £1,400 fitted
uPVC doors cost £700 to £1,400 fitted. Where they make sense, why cheap ones drop on their hinges, and the cylinder upgrade worth paying for.
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Aluminium doors
£1,400 – £2,800 fitted
Aluminium doors cost £1,400 to £2,800 fitted. Why the material handles tall, heavily glazed doors, and how to match it across the house.
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Sliding patio doors
£1,500 – £4,000 fitted
Sliding patio doors cost £1,500 to £4,000 fitted. Bigger panes than bi-folds, no lost space, and why lift-and-slide changes how they feel.
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French doors
£1,200 – £2,950 fitted
French doors cost £1,200 to £2,950 fitted. Usually the sensible answer up to two metres, with no track or running gear to wear out.
TrustedGlazing does not make, supply or fit windows and doors, and the prices above are published industry guides rather than our own. We match your enquiry to one vetted local installer, who quotes and contracts with you directly.