How much do bifold doors cost in the UK? (2026)

A typical UK bifold door set installed in 2026 costs £1,950 to £4,670 for a 3-panel set depending on material, rising to £5,260 to £7,200 for a 5-panel aluminium set, and £10,000 to £15,000+ for wide 6 or 7-panel openings. Each extra leaf adds roughly £700 to £1,000. Prices cover supply and fit into an existing opening; forming a new opening adds £2,000 to £4,000 for structural work and Building Regs. VAT is 20% (bifolds are not on the energy-saving materials zero-rate list).

How to read this guide#

Two kinds of figures appear below:

• Headline price ranges (per-material, per-panel-count, labour, structural extras): cross-referenced against MyJobQuote, Expertsure, and the FENSA / Building Regs framework.
• Practical guidance (material choice, spec, threshold types, what the price should include, red flags): drawn from standard UK glazing installation practice.

Where a figure could not be verified across multiple sources, it is flagged or described qualitatively.

Headline ranges (verified)#

Installed cost by material and panel count#

(MyJobQuote, Expertsure, 2026.) Each additional leaf beyond 5 adds roughly £700–£1,000. Wide 6 or 7-panel aluminium sets spanning a full extension wall (5–7 m) typically land at £8,000–£15,000+ installed, before structural work.

Labour, supplied separately#

Structural and Building Regs (new or widened opening)#

Combined, new-opening work commonly adds £2,000–£4,000 on top of the doors, more for a full kitchen-extension rear wall with a wide beam.

Spec upgrades#

VAT#

• 20% standard VAT on bifold doors, fitted. They are not on the energy-saving materials zero-rate list (GOV.UK), which covers solar, heat pumps, insulation, and similar — but not windows or doors.

Practical guidance (industry standard)#

Aluminium vs uPVC vs timber: pick the right material for the span#

Aluminium is the default for openings over about 3.5 m. The frame profile is slim (50–100 mm sightlines), each leaf can be up to 1.2 m wide, and the structural rigidity holds up across 5+ panel spans. Almost every kitchen-extension rear wall is aluminium for this reason.

uPVC is the cheapest option and works fine for smaller openings (3-panel, up to about 3 m). The frame profile is chunkier (80–120 mm sightlines), each leaf is narrower, and most uPVC bifolds cap out at 4 panels because wider spans cause the frames to flex.

Timber sits between the two on price but is heavier per leaf and needs ongoing finishing (oil or paint every 3–5 years on exposed elevations). Suits period properties where aluminium looks wrong, and conservation areas where timber may be a planning condition.

Composite (aluminium outer, timber inner) gives the slim sightlines of aluminium with a warm internal finish, at roughly 80–90% of the aluminium price. A premium choice rather than a value one.

What a typical bifold door quote should cover#

A complete supply-and-fit bifold quote should include:

• The door set (frames, leaves, glazing, hardware, finish)
• Removal and disposal of the existing doors or windows
• Fitting into the existing opening, including weatherproofing, trickle vents (Part F), and final sealing
• FENSA or Certass self-certification under Part L of Building Regs
• A 10-year insurance-backed guarantee on the doors
• Adjustment and final commissioning (bifolds need careful alignment; poorly adjusted leaves bind or drop within months)

It often does not cover:

• Forming a new opening or widening an existing one (structural work)
• The lintel or steel beam, structural engineer, and Building Regs fees that come with structural work
• Internal making-good after structural work (plastering, decoration, flooring at the threshold)
• External making-good (brick or render repair around the new opening)
• Floor finishes that need to butt up to the new threshold
• A flush threshold upgrade (most quotes default to a rebated threshold, which has a 50–70 mm step)
• Scaffolding for upper-floor or full-height openings
• Toughened or laminated glass upgrades beyond the standard double glazing the quoted unit comes with

When you compare bifold quotes, the easy mistake is comparing a £6,500 "all-in" aluminium quote against a £4,500 "doors only" quote that excludes the steel beam, the engineer's fee, Building Control, and plastering. Read the inclusions list line by line, and see our hidden costs checklist for the full pattern across trades.

Why FENSA (or Certass) matters#

FENSA and Certass are competent-person schemes that let the installer self-certify compliance with Part L of Building Regs (the 1.4 W/m²K U-value rule for new and replacement doors). Without it, you need a separate Building Control inspection (£200–£500) for what is otherwise a straightforward replacement.

A FENSA certificate is also what a conveyancer will look for when you sell the house. Bifolds installed without it are a future legal-pack problem: either you pay for retrospective Building Regs sign-off, or the buyer's solicitor will push for an indemnity policy.

A non-FENSA quote should come in cheaper by at least the £200–£500 Building Control fee to be competitive on like-for-like terms, and usually doesn't.

The threshold question: rebated vs flush#

The default threshold on most bifold quotes is rebated (also called weathered): a raised aluminium track 50–70 mm above the internal floor, with a downstand on the outside that sheds water. Reliable in weather but a visible step.

A flush threshold sits at the same level as the internal floor, with a small drainage channel concealed under the doors. Looks much better in a kitchen extension where you want continuous flooring inside-to-outside, but adds £100–£300 to the door cost and needs the external level to be set 5–10 mm below the internal floor (so an extension build needs to anticipate it).

If you are mid-extension and the slab has already been poured at internal-floor level, you cannot retrofit a flush threshold without re-cutting external levels. Decide before the slab goes down.

Glazing spec: what to ask for and why#

Standard spec on most bifold quotes is double-glazed, low-E coated, argon-filled, 28 mm sealed units. This gives a U-value around 1.4 W/m²K, meeting Part L.

Triple glazing brings the U-value down to 1.0–1.2 W/m²K and is worth specifying for north-facing or exposed elevations, or if you will be running underfloor heating into the doorway. Adds 10–15%.

Toughened or laminated glass is required under Building Regs within 800 mm of floor level on any glazed door, which applies to the full height of every bifold leaf. Reputable installers include this as standard; check it appears on the quote.

Solar control coating is worth specifying for south or west-facing openings to reduce summer overheating. Adds 5–10%.

Integral blinds between panes look neat but add £200–£500 per leaf and are a single point of failure: if the mechanism fails after warranty, the whole unit needs replacing.

Red flags in bifold door quotes specifically#

Beyond the standard quote red flags (covered separately), bifold quotes have their own:

No U-value stated. Without a number, you cannot tell if the doors meet Part L. A serious supplier states the U-value of the supplied units on every quote.

No FENSA or Certass registration. Means you pay £200–£500 extra for Building Control on what should be a self-certified replacement, and you have a missing certificate when you sell.

Brand not named. "Premium aluminium bifolds" with no system named (Schüco, Origin, Sunflex, Smart, Reynaers, etc.) is a way of leaving the specification vague. Get the system and the leaf-width limit in writing.

"VAT to be confirmed" or no VAT line. Bifolds are 20% VAT, full stop. A quote that leaves it ambiguous is one where the 20% is about to land on a "revised quote" later. See does a builder's quote include VAT.

No mention of the threshold type. Defaults to a rebated threshold with a step. If you want flush, it needs specifying upfront so the external levels and drainage are set correctly.

Structural work tucked into a single "preparation" line. A new opening needs a structural engineer, a specified lintel or beam, Building Control sign-off, and making-good. A single £1,500 "prep" line is hiding two or three jobs that should each be priced.

A quote that doesn't include the steel. If your project involves widening an existing opening, the steel beam should be a separate line, not a "we'll let you know nearer the time" assumption. This is the single most common scope gap that turns a £6,000 quote into a £9,000 invoice.

"Same-day install" on a 5-panel set. A proper 5-panel install is 2 days, including alignment and commissioning. A 1-day blast on a wide opening typically means the door leaves are not properly adjusted and will drop or bind within 6 months.

When bifolds are not the right answer#

Bifolds work well when you want the full opening open in summer (every leaf folds back to one side), but they have downsides worth weighing against sliding doors before committing:

• Sightlines are wider when closed. A 5-panel bifold has 4 vertical frame meeting-points across the opening. A 3-panel slider has 2. For "view-through" priorities, sliders look better closed.
• Operating leaf in winter. Most bifolds have a separate "traffic" door that opens like a normal hinged door for daily use; if yours doesn't, you fold back 2–3 panels every time you nip out. Specify the traffic door upfront.
• Threshold compromise. The rebated threshold step is worse on bifolds than on sliders because you walk over it more often.
• Cost per metre of opening. For a 4 m+ opening, premium sliders (Schüco ASS 70, Reynaers Hi-Finity) are often cheaper than equivalent-spec bifolds.

If the priority is summer-time full opening, bifolds are right. If the priority is winter-time view and daily access, sliders usually win.

Comparing your bifold quote#

The quote checker on this site analyses each line against current UK rates, flags missing scope (steel beam, Building Regs fees, FENSA certification, threshold spec, glazing upgrade, making-good), and runs a Companies House check on the installing company. For a £6,000 to £12,000 bifold install (often part of a much larger extension quote, see house extension costs), the £14 cost is small relative to the decision; the information returned is what turns "this quote looks roughly fair" into "every line is accounted for".