The short answer
For most standard widths, bifold and sliding doors cost broadly similar amounts, though large fixed-pane sliding doors with very slim frames can become the more expensive option. In the UK a mid-range aluminium bifold and a comparable aluminium slider often land within a few hundred pounds of each other. Bifolds use more hinges and panels, while premium sliders use heavy oversized glass and minimal frames, so each has its own cost drivers. At everyday three to four-metre openings the price is close; at very wide spans with large single panes of glass, sliding systems can pull ahead on cost. Specification matters more than the mechanism alone.
Bifolds and sliders are close on price at typical sizes, so the decision usually rests on how you want the opening to look and work rather than cost alone.
Quick reference
- Bifold fitted (3-4 pane)£3,500–£6,500
- Sliding fitted (2-3 pane)£3,000–£7,000
- Slimline / large-pane slider£5,000–£12,000+
- Cost driverGlass size & frame slimness
Indicative price comparison
The table shows indicative UK 2026 fitted ranges for aluminium bifold and sliding doors at common openings. Both scale with width, but their cost drivers differ, so the ranges overlap at typical sizes and diverge at the extremes.
At around 2.4 to 3 metres, a standard bifold and a standard slider are usually within a few hundred pounds of each other. The picture changes with premium slimline sliders that use very large, heavy panes of glass and minimal frames, which sit well above a comparable bifold. Glazing upgrades and threshold choices affect both.
| Opening | Bifold (fitted) | Sliding (fitted) |
|---|---|---|
| 2.4m | £3,000–£5,500 | £3,000–£6,000 |
| 3.0m | £4,000–£6,500 | £3,500–£7,000 |
| 4.0m+ | £5,000–£9,000+ | £5,000–£12,000+ |
Indicative UK figures; slimline large-pane sliders sit at the top of the range.
Why the costs are close
The two door types reach a similar price by different routes. A bifold's cost comes from multiple panels, hinges and a folding track. A slider's cost comes from large, heavy panes of glass and the running gear needed to move them on a track. Key points:
- Bifolds: more frame and more moving parts, but standard glass sizes.
- Sliders: fewer panels but much larger individual panes, which are heavier and pricier to make and transport.
- Slim-frame premium sliders with minimal sightlines carry a clear premium over standard systems.
- Both rise with width, glazing upgrades and threshold type.
Because the cost drivers differ, the cheaper option depends on the exact specification. A standard slider can undercut a bifold at a modest width, while a premium architectural slider with oversized glass can cost far more than any bifold.
Beyond price: how they differ
Since the cost is often similar, the choice usually comes down to the result. Bifolds fold almost completely clear, opening up the whole span to a garden, but the folded panels stack to one side and the frames break up the view when closed. Sliders keep large uninterrupted panes of glass for a cleaner view, but only part of the opening is ever clear because one panel slides behind another.
Bifolds suit those who want to throw the wall fully open and enjoy an uninterrupted threshold in summer. Sliders suit those who prioritise the view and easy everyday operation, since a single panel glides aside with little effort. Maintenance, cleaning access and threshold detailing also feed into the long-term picture, as does the stacking space a bifold needs to one side when folded back.
Which works out cheaper for your project
To decide which is cheaper for your specific job, price both for the same opening and specification. For a standard patio-sized opening with everyday glazing, a slider and a bifold are likely to be close, and the choice can rest on preference rather than cost. For a wide opening where you want the cleanest possible view with the largest panes, a premium slider may cost more, while a bifold delivers the wide-open feel at a more moderate price.
Remember that the structural opening, lintel and making good are usually similar for either door, so they do not tip the balance. The deciding factors are the glazing specification, frame slimness and the door system used. Getting like-for-like quotes for both types lets you see the real difference for your project rather than relying on a general rule, since the answer genuinely depends on the size and finish you choose.
When you gather those quotes, make sure each one describes the same specification so the comparison is fair. A bifold quoted with a flush threshold and triple glazing will naturally cost more than a slider quoted with a standard threshold and double glazing, even if the slider is the dearer system like for like. Check that both include the same glazing, the same threshold detail, removal and disposal of the old doors, and the same making good around the reveals. Ask whether the glass specification, the frame colour and any solar-control coating match across the two prices. Only when the scope is identical does the headline figure tell you which mechanism actually costs more for your opening. With matched quotes in front of you, the decision usually comes back to how you want the opening to look and work, because the price difference at typical sizes is often smaller than the difference in everyday experience.
Frequently asked questions
Which is more energy efficient, bifold or sliding?
Both can achieve good thermal performance with quality double or triple glazing and thermally broken aluminium frames. Sliders have fewer joints, while bifolds have more seals; well-made examples of each perform similarly.
Are sliding doors better for small openings?
For narrow openings, sliders and even French doors can be simpler. Bifolds show their advantage at wider spans where folding several panels clear makes a bigger difference to the indoor-outdoor connection.
Do sliding doors need more maintenance than bifolds?
Both need their tracks kept clean and rollers lubricated. Bifolds have more hinges to check, while sliders have heavier panels on the running gear; routine care keeps either working smoothly.
Why are some sliding doors so expensive?
Premium slimline sliders use very large, heavy panes of glass and minimal frames, which are costly to manufacture, transport and install. That specification, not the sliding mechanism itself, drives the high prices.
Do bifolds let in more light than sliders?
When closed, sliders often show more glass and fewer frames, so they can feel lighter. When open, bifolds clear almost the whole opening. Which feels brighter depends on whether the doors are usually open or closed.
Sources & further reading
- Checkatrade — bifold door cost guide
- Checkatrade — sliding patio door cost guide
- HomeOwners Alliance — bifold doors guide
Figures on this page are typical UK ranges drawn from published sources and depend on your specific opening and material. They are guidance, not a quotation.