Bi-Fold Doors

Bi-Fold Doors

Open up an entire wall. Bring the outside in.

Bi-fold doors are the most effective way to maximise the connection between interior living spaces and outdoor areas. When fully open, the entire wall folds neatly to one or both sides — flooding the room with natural daylight and fresh air in a way no other door type can match.

We supply bi-fold doors in two product lines: a Liniar uPVC bi-fold for standard residential applications, and a Smart Systems aluminium bi-fold for larger openings and heavy-duty applications, designed to match seamlessly with the Liniar uPVC window range.

Liniar uPVC Bi-Fold Doors

Our uPVC bi-fold is built on the Liniar multi-chambered profile system — a lead-free, anti-static design that outperforms most leading UK brands on thermal efficiency, with ultra-slim sightlines for a modern, clean aesthetic.

Key Features

Ultra-slim sightlines	Less frame, more glass — the slim profile delivers a modern, uncluttered appearance and maximises the glazed area for natural light and unobstructed views.
Multi-chamber thermal efficiency	The Liniar profile system outperforms most leading UK brands in thermal efficiency. A door’s energy performance is measured in U-values — the lower the U-value, the better the insulation. Available from entry-level C-rated to A+ energy rating.
Lead-free construction	The system uses unique PVC inserts in place of traditional steel reinforcing, delivering equivalent tensile strength with a safer environmental profile and superior long-term thermal performance.
Innovative low threshold	A patented low threshold solution requires no expensive or messy excavation — making it both family friendly and wheelchair accessible without the disruption of a traditional installation.
Slim hinges with hidden fixings	Hidden internal fixings preserve the clean sight lines and increase security — it is impossible to unscrew the hinges from the outside.
Smooth easy action	Designed for effortless operation across all panel configurations, with folding keys included to avoid any issues with keys left in locks during use.
Hook locking with shootbolts	Fitted with the most robust locking mechanisms on the market as standard. Secured by Design upgrade available on request.
8mm sash coverage	Best-in-class rating for air leakage, contributing to the system’s overall thermal and acoustic performance.
Patented double-action gasket	Delivers 30% better compression than standard gasket systems — improving weather sealing and draught resistance across the full door width.
Centralised Euro groove	Provides improved strength and security at the sash meeting rail.
Factory-fitted glazing efficiency	32mm channel packers are factory fitted with toe and heel packers in position, resulting in faster, safer on-site glazing. Square cut and scribed beading and single J-leg security beads are included for ease of installation.
Flexible coupling and add-on options	Frames couple in multiple configurations including patio and casement window arrangements. 10mm, 20mm and 50mm add-on widths available for every installation.

Liniar uPVC Bi-Fold — Technical Specification

Specification	Detail
Profile system	Liniar uPVC — lead-free, anti-static
Energy rating	C-rated to A+ (dependent on specification)
Minimum sash size	600mm wide x 1850mm high
Maximum sash size	800mm wide x 2150mm high
Sash coverage	8mm (best rating for air leakage)
Gasket	Patented double-action — 30% better compression
Locking	Hook locking with shootbolts
Security upgrade	Secured by Design available on request
Threshold	Patented low threshold — no excavation required
Glazing packers	32mm channel packers factory fitted
Hinges	Slim hinges with hidden internal fixings
Add-on widths	10mm, 20mm and 50mm
Configurations	Multiple — including patio and casement combinations
Profile warranty	10 years

Opening Configurations

The Liniar uPVC bi-fold is available in a wide range of standard panel configurations to suit any opening width. Panels can fold to the left, right or both sides, with a traffic door option available for everyday access without opening the full set. Speak to our team for a configuration diagram to suit your specific opening.

Smart Systems Aluminium Bi-Fold Doors

Our aluminium bi-fold uses the Smart Systems aluminium profile — a true aluminium door, not a multi-material clad hybrid — engineered specifically for larger openings and more heavy-duty applications where uPVC’s maximum sash width is a limiting factor.

The aluminium bi-fold delivers sculptured lines, low U-values and a foiled exterior that matches seamlessly with the Liniar uPVC window range.

Why Choose the Aluminium Bi-Fold?

Larger maximum sash size	Maximum sash size of 1200mm wide x 2500mm high — significantly larger than the uPVC bi-fold — making this the right choice for wide or tall openings where uPVC reaches its structural limits.
Superior thermal performance	U-values as low as 1.2 W/m²K — more energy efficient than most aluminium bi-fold doors on the market, with an energy rating range from C to A+.
True aluminium — not a hybrid	Multi-material clad hybrid bi-folds require specialist machinery, complex fabrication and hide the thermal benefits inside the profile. This is a true aluminium door, with visible sculptured lines that deliver genuine aesthetic and structural integrity.
Sculptured profile matching uPVC windows	The profile is designed to match the sculptured aesthetic of the Liniar uPVC window system — the ideal choice where the door needs to sit alongside existing or new Liniar uPVC windows without a visual mismatch.
Foiled exterior	The exterior can be foiled to match or complement the uPVC window range, delivering colour consistency across an entire elevation.
Warm touch exterior	Despite being aluminium, the door features a warm touch exterior — addressing the common complaint that aluminium profiles feel cold to handle in low temperatures.
Robust locking mechanisms	Hook locking with shootbolts fitted as standard — the most robust locking system available. Secured by Design upgrade available on request.
Smooth easy action	Engineered for effortless operation even on larger, heavier panel configurations.

Aluminium Bi-Fold — Technical Specification

Specification	Detail
Material	True aluminium — not a hybrid or clad system
Profile system	Smart Systems
U-value	As low as 1.2 W/m²K
Energy rating	C-rated to A+ (dependent on specification)
Minimum sash size	600mm wide x 1850mm high
Maximum sash size	1200mm wide x 2500mm high
Locking	Hook locking with shootbolts
Security upgrade	Secured by Design available on request
Exterior finish	Foiled exterior available — matches Liniar uPVC window range
Profile aesthetic	Sculptured to match Liniar uPVC window profile
Profile warranty	10 years

uPVC vs Aluminium — Which is Right for Your Project?

	Liniar uPVC Bi-Fold	Smart Systems Aluminium Bi-Fold
Material	Liniar uPVC profile	True aluminium
Max sash width	800mm	1200mm
Max sash height	2150mm	2500mm
U-value	C to A+ rated	As low as 1.2 W/m²K
Reinforcing	PVC inserts (no steel)	Aluminium structural frame
Exterior finish	Full colour/foil range	Foiled to match uPVC range
Profile match	Liniar uPVC windows	Liniar uPVC windows (sculpted match)
Low threshold	Patented — no excavation	Available
Security	Hook lock + shootbolts	Hook lock + shootbolts
SBD upgrade	Available on request	Available on request
Best suited for	Standard residential openings up to 800mm per sash	Larger or heavy-duty openings, new build, extensions
Price position	Cost effective	Premium

Colours

Both the uPVC and aluminium bi-fold ranges are available in a full colour range. Stocked colours are available for standard lead times; special order foiled options extend the palette further.

Option	Detail	Lead Time
Standard stocked	White, Rosewood, Cream, Irish Oak, Light Oak and other core colours	From stock
Special order — foiled one side	Extended colour range including Chartwell Green, Grey, Black and bespoke foils	5–6 weeks
Special order — foiled both sides	Dual-colour foiled finish — different colour inside and out	7–8 weeks
Colour-matched flag hinges	Available on request to complement coloured door specifications	On request

Note: Resurgence and astragal bar orders require additional production time above the lead times shown.

Frequently Asked Questions

What are bi-fold doors?

Bi-fold doors consist of multiple panels that fold and stack neatly to one or both sides of the opening, allowing the entire wall to be opened up. They are typically used to connect interior living spaces — kitchens, dining rooms and living rooms — to gardens, patios and terraces, and are available in both uPVC and aluminium.

What is the difference between uPVC and aluminium bi-fold doors?

uPVC bi-folds use the Liniar multi-chamber profile system and are the more cost-effective option, with a maximum sash size of 800mm x 2150mm. The aluminium bi-fold uses the Smart Systems profile for a true aluminium product with a maximum sash size of 1200mm x 2500mm, U-values as low as 1.2 W/m²K, and a sculptured profile designed to match the Liniar uPVC window range. Aluminium is the right choice for larger or more heavy-duty applications.

How many panels can a bi-fold door have?

Our bi-fold doors are available in a wide range of standard configurations from two panels upwards, folding to the left, right or both sides. The exact panel count depends on the overall opening width and individual sash sizes. Contact our team for a configuration diagram specific to your opening.

Do bi-fold doors have a traffic door?

Yes — a traffic door option is available, allowing a single panel to be opened for everyday access without unfolding the entire set. This is particularly useful for larger configurations where opening all panels for routine access would be impractical.

Are bi-fold doors thermally efficient?

Yes. The uPVC bi-fold uses the Liniar multi-chambered profile which outperforms most leading UK brands on thermal efficiency, achieving C to A+ energy ratings. The Smart Systems aluminium bi-fold achieves U-values as low as 1.2 W/m²K — more thermally efficient than most aluminium bi-folds on the market.

Are bi-fold doors secure?

Hook locking with shootbolts is fitted as standard on both the uPVC and aluminium ranges — described as the most robust locking mechanism available. The uPVC bi-fold also features hidden hinge fixings that cannot be unscrewed from the outside. Secured by Design upgrade is available on request for both product lines.

What threshold options are available?

The uPVC bi-fold features a patented low threshold solution, which requires no excavation — making it family and wheelchair friendly without the disruption of a traditional flush threshold installation. Threshold options are also available for the aluminium range — speak to our team for the full specification.

What is the maximum size for a bi-fold door?

For uPVC: maximum sash size is 800mm wide x 2150mm high. For aluminium: maximum sash size is 1200mm wide x 2500mm high. The overall door width depends on the number of panels and configuration specified.

Can bi-fold doors be colour matched to my existing windows?

Yes. Both ranges are available in a full colour palette, and the aluminium bi-fold’s foiled exterior is specifically designed to match the Liniar uPVC window range — making it the natural choice where colour consistency across the elevation is important.

What warranties are included?

A 10-year profile warranty applies to both the uPVC and aluminium bi-fold ranges. Additional component warranties may apply — speak to our team for the full warranty schedule at point of quotation.

Ready to specify?

Request a quote for uPVC or aluminium bi-fold doors — our team can advise on configuration, sizing, threshold and colour options for your project.