Aluminium bifold doors

Our SUNFLEX aluminium bifold doors add a special touch to every home design project. These exciting installations break down the boundaries between indoor and outdoor space for the ultimate enjoyment of your surroundings.

Aluminium bifold door in a contemporary interior designed room

The SF55s and SF75 systems utilise the latest in thermal break technology, separating the internal and external faces of aluminium, providing excellent thermal properties. This enables SUNFLEX to manufacture some of the most advanced energy-efficient bifold door systems available.

Our range of SUNFLEX aluminium bifold doors provides a contemporary, modern look and a maintenance-free solution. With minimal sight lines, over 200 different colours, and single, double or triple glazing, this range will meet the demands of any project.

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Award winning

The Sunflex SF55s aluminium bifold door system was named 'Best Glazed Door' by Build It magazine. The door was recognised for its sleek profile and slimline frames with door panels just 55mm front to back, creating a wider opening than any other folding door available. And it is the neatest stack of doors on the market.

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Ten-year warranty

You can rely on the high quality of the SUNFLEX products we install, and buy with confidence with a full ten-year warranty* on our systems and workmanship. Plus, unlike some warranties, our guarantee is fully transferable if you decide to sell your home.

*Exclusions apply, please contact us for full details of warranty policy.

Secured by Design logo

High security

IDSystems is proud to have received the coveted Secured by Design Award for bifold doors – with the systems achieving Police-preferred specification for design and manufacture. The Secured by Design initiative aims to reduce crime by ensuring the effective design and installation of products to meet Police-approved security standards.

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Thermally efficient

Specifically designed to offer the best in thermal efficiency and extremely low U-Value, providing the lowest in CO2 emissions associated with reduced energy consumption and considerable savings in heating bills. The SF75 can achieve industry leading thermal performance, with U-values from just 0.8W/m2K (based on a centre-pane of 0.5W/m2K), enabling the bifold doors to be installed on projects constructed to Passivhaus standard.

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Smooth operation

All SUNFLEX bifold doors are fitted with unique running carriages that mount to the door frame rather than the hinge. This provides the smoothest operation, enhanced security and neat visual appearance.

Bifold doors with midrails

Optional glazing bars

For those seeking to add an Art-Deco style to their bifold doors, we can add narrow glazing bars (alternatively known as mid-rails or plant-on bars) to the design of the doors to provide the much sought-after look of traditional neo-industrial steel doors.

Case studies featuring bifold doors

Green-roofed, timber clad extension to a Victorian villa

This challenging project saw this Victorian villa extended to create an open plan living space filled with natural light. The largely glazed timber (sustainably sourced) clad extension houses the kitchen and dining area and facing the garden.

Luxury Edinburgh garden room guest apartment

Creating a luxury garden room apartment from an old stone store may not have been the most obvious route to take for the owners of this property in Edinburgh, but that is exactly what Sally and Dan Weatherly achieved.

Conversion of Victorian Methodist chapel

The complete, yet sensitive, renovation of this Victorian red-brick Methodist chapel overlooking an area of outstanding natural beauty required an innovative design to create a contemporary family home flooded with natural light throughout.

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    Aluminium bifold door showing large frames and wide opening

    All SUNFLEX bifold doors are fitted with unique running carriages that mount to the door frame rather than the hinge. This provides the smoothest operation, enhanced security and neat visual appearance.

    The bifold door panels can be made up to 1200mm wide and 2800mm high, while greater heights can be achieved by using sliding posts to achieve tall bifold doors up to 3500mm in height.

    Our range of SUNFLEX aluminium bifold doors

    SUNFLEX SF55s

    Award-winning aluminium bifold door system packed full of unique features

    SUNFLEX SF55v

    Innovative versatile bifold doors with the ability to open and stack to the same side

    SUNFLEX SF75

    Highly engineered, ultra-thermally efficient aluminium bifold doors

    SUNFLEX SF55s

    Award-winning aluminium bifold door system packed full of unique features

    The award-winning SUNFLEX SF55s sets the standard for the aluminium bifold door market and is amongst the most advanced aluminium bifold doors available, making it
    perfect for more complex configurations that include moveable corner posts or for extreme panel sizes.

    SUNFLEX SF55v

    Innovative versatile bifold doors with the ability to open and stack to the same side

    The SUNFLEX SF55v versifold door is an innovative addition to the range of thermally broken aluminium systems available from IDSystems. Designed to allow customers to stack all of the panels up to the opening end of the door system.

    SUNFLEX SF75

    Highly engineered, ultra-thermally efficient aluminium bifold doors

    The SUNFLEX SF75 bifold doors have been specifically designed to provide the ultimate in thermal efficiency with an incredible low U-value from just 0.9W/m2K when triple glazed. The SF75 enjoys all the design features and benefits of the award-winning SF55s.

    Sight lines (intermediate frame widths)

    Having narrow sight lines maximises the view. Our bifold doors are engineered to have the thinnest possible sight lines.

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    SUNFLEX SF55s

    115mm

    SUNFLEX SF55v

    115mm

    SUNFLEX SF75

    115mm

    Frame depths

    We design our bifold doors so, when stacked, they provide a slim profile that maximises space and when closed they look narrow whichever angle they are viewed from

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    SUNFLEX SF55s

    55mm

    SUNFLEX SF55v

    55mm

    SUNFLEX SF75

    75mm

    Thermal performance

    Thermal performance of the doors is measured as a U-value. When comparing products it is crucial to compare the overall U-value of the system and not just the U-value of the sealed glass unit. The SUNFLEX bifold doors can achieve incredibly low U-values based on a centre-pane of 0.5W/m²K, with the SF75 capable of achieving a figure low enough for use on Passivhaus standard projects.

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    SUNFLEX SF55s

    Double glazed: from 1.1W/m²K.

    SUNFLEX SF55v

    Double glazed: from 1.1W/m²K.

    SUNFLEX SF75

    Triple glazed: from 0.8W/m²K.

    Panel sizes

    The maximum size of each individual glass panel installed in our sliding doors range.

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    SUNFLEX SF55s

    Width: up to 1200mm. Height: up to 3500mm

    SUNFLEX SF55v

    Width: up to 1100mm. Height: up to 3000mm

    SUNFLEX SF75

    Width: up to 1200mm. Height: up to 3500mm

    Opening direction

    Whilst the majority of bifold doors are installed in an outward opening configuration, inward opening doors are ideal for use with balconies or with small courtyard gardens.

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    SUNFLEX SF55s

    Inwards or outwards opening, stacking to one end

    SUNFLEX SF55v

    Inwards or outwards opening, stacking to either end

    SUNFLEX SF75

    Inwards or outwards opening, stacking to one end

    Gaskets

    The gaskets that seal the panels of the doors together when closed, providing a weather-tight seal, are made from an incredibly durable, synthetic EPDM rubber.

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    SUNFLEX SF55s

    Continuous triple rebated gaskets

    SUNFLEX SF55v

    Gasket one side of the panel interlocking in to the next panel

    SUNFLEX SF75

    Continuous triple rebated gaskets

    Thermal break

    Separating the external and internal aluminium frames of the door the polyamide thermal breaks prevent cold bridging, increasing the thermal performance of the system.

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    SUNFLEX SF55s

    Patented 24mm polyamide thermal break

    SUNFLEX SF55v

    Patented 24mm polyamide thermal break

    SUNFLEX SF75

    Patented 44mm multi-chambered polyamide thermal break

    Security

    Our bifold doors include shoot bolt locks that extend from the lead door and intermediate panels into the top and bottom of the track, whilst the lead door features a mushroom head lock into the side jamb.

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    SUNFLEX SF55s

    Multipoint locking with shoot bolts hidden in the top and bottom of the door panels and mushroom head lock on lead door.

    SUNFLEX SF55v

    Multipoint locking with shoot bolts hidden in the top and bottom of the door panels and mushroom head lock on lead door.

    SUNFLEX SF75

    Multipoint locking with shoot bolts hidden in the top and bottom of the door panels and mushroom head lock on lead door.

    BSI Kitemark™

    Independently certified for quality assurance to prestigious BSI Kitemark™ standards.

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    SUNFLEX SF55s

    Yes. Certificate No. 643635

    SUNFLEX SF55v

    Yes. Certificate No. 643635

    SUNFLEX SF75

    Yes. Certificate No. 643635

    PAS 24:2016 / Building Regulations Document Q compliant

    PAS 24:2016 is the testing standard for security required to comply with Building Regulations Document Q. P1a glass (usually laminated glass) specification is required to meet Building Regulations Document Q approval.

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    SUNFLEX SF55s

    Yes

    SUNFLEX SF55v

    Yes

    SUNFLEX SF75

    Yes

    Secured by Design

    The Secured by Design award marks the police preferred security specification for windows and doors

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    SUNFLEX SF55s

    Yes

    SUNFLEX SF55v

    Yes

    SUNFLEX SF75

    Yes

    Glazing options

    Double glazing is a minimum requirement for external doors and windows. Our standard double glazed units consist of a soft-coat Low-E (low emissivity) pane and argon gas-filled cavity which provides a centre pane U-Value of 1.2W/m2K. Over the standard, we can provide super-insulated double glazed units providing a centre pane U-Value of 0.5W/m2K whilst providing solar control.

    Triple glazing is becoming increasingly popular, especially in total new builds, as it provides the lowest U-Values possible and can be up to 40% more efficient than double glazing. Combining two panes of Low-E glass and two gas-filled cavities, glazing U-Values as low as 0.5W/m2K are possible with the added benefit of great sound reduction.

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    SUNFLEX SF55s

    Double glazed as standard

    SUNFLEX SF55v

    Double glazed as standard

    SUNFLEX SF75

    Triple glazed as standard

    Manufactured in

    Each set of our bifold doors is handmade to the highest standards or quality and performance by experienced fabrictors

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    SUNFLEX SF55s

    Germany

    SUNFLEX SF55v

    Germany

    SUNFLEX SF75

    Germany

    Severe weather rating

    Every set of doors and windows undergoes independent physical testing to assess the ability of the systems to withstand air and water. Water tightness is tested against BS EN 12208 standard with air permeability tested against BS EN 12207 standard.

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    SUNFLEX SF55s

    Water tightness: 900Pa (Class 9a). Air permeability: 600Pa (Class 4)

    SUNFLEX SF55v

    Water tightness: 600Pa (Class 7a). Air permeability: 300Pa (Class 3)

    SUNFLEX SF75

    Water tightness: 900Pa (Class 9a). Air permeability: 600Pa (Class 4)

    Track options

    Our bifold doors come with a choice of track options. Non-weather rated flush tracks are only typically recommended for internal or sheltered urban locations. Low-threshold tracks have 14mm upstands are ideal for urban or rural locations, with our fully weathered tracks designed for rural or exposed locations.

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    SUNFLEX SF55s

    3 – flush, low-threshold or weathered track

    SUNFLEX SF55v

    3 – flush, low-threshold or weathered track

    SUNFLEX SF75

    2 – low-threshold or weathered track

    Locking panel catch

    A truly unique and innovative feature, the SUNFLEX locking panel catch holds the lead door of the system in place when the doors are being opened, preventing the door from swinging shut.

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    SUNFLEX SF55s

    Yes

    SUNFLEX SF55v

    Yes

    SUNFLEX SF75

    Yes

    Stacking clip

    Unique to SUNFLEX bifold doors, the exclusive stacking clip holds the doors securely in place when they are stacked open, stopping the wind (or young children) closing the doors unexpectedly.

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    SUNFLEX SF55s

    Yes

    SUNFLEX SF55v

    No

    SUNFLEX SF75

    Yes

    Running gear

    Our bifolds are manufactured with two styles of running gear, both ensuring ease of use and ultra-smooth operation of the doors.

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    SUNFLEX SF55s

    Concealed stainless steel running gear connected to the frame of the doors

    SUNFLEX SF55v

    Nylon covered stainless steel wheels connected to the hinge of the door

    SUNFLEX SF75

    Concealed stainless steel running gear connected to the frame of the doors

    Moveable corner posts

    The integration of a moveable corner post allows the doors to open up a complete, unobstructed corner of a room

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    SUNFLEX SF55s

    Yes, for 90° or 135° corners

    SUNFLEX SF55v

    No

    SUNFLEX SF75

    Yes, for 90° or 135° corners

    Colour choices

    Our doors are available in a range of standard colours, alternatively you can select from an almost infinite choice of optional colours and finishes – or even opt for a dual colour door with different colours on the internal and external frames.

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    SUNFLEX SF55s

    Standard – Anthracite Grey (RAL 7016) semi-gloss, White Aluminium (RAL 9006) semi-gloss, Grey Aluminium (RAL 9007) semi-gloss, Traffic White (RAL 9016) semi-gloss and Anodised Silver. Optional - More than 200 RAL colours and finishes are available as an optional extra

    SUNFLEX SF55v

    Standard – Anthracite Grey (RAL 7016) semi-gloss, White Aluminium (RAL 9006) semi-gloss, Grey Aluminium (RAL 9007) semi-gloss, Traffic White (RAL 9016) semi-gloss and Anodised Silver. Optional - More than 200 RAL colours and finishes are available as an optional extra

    SUNFLEX SF75

    Standard – Anthracite Grey (RAL 7016) semi-gloss, White Aluminium (RAL 9006) semi-gloss, Grey Aluminium (RAL 9007) semi-gloss, Traffic White (RAL 9016) semi-gloss and Anodised Silver. Optional - More than 200 RAL colours and finishes are available as an optional extra

    Integral blinds

    We are able to fit integral Venetian blinds within the glazed unit, ensuring a totally dust-free environment which requires no cleaning or maintenance. These are very popular, especially on internally opening systems where curtains are not practical.

    Integrated blinds can be tilted to help prevent the build-up of excessive heat and glare of the sun during the daytime and provide privacy when closed. Blind units are manually operated with an ingenious magnetic control device.

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    SUNFLEX SF55s

    Optional

    SUNFLEX SF55v

    Optional

    SUNFLEX SF75

    Optional

    Trickle vents

    The requirement for trickle vents to provide background ventilation can be a requirement of Building Regulations Document F, depending on the type of project you are undertaking. IDSystems trickle vents are installed through the head track of the outer frame if required.

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    SUNFLEX SF55s

    Optional

    SUNFLEX SF55v

    Optional

    SUNFLEX SF75

    Optional

    Glass options

    Laminated glass: Improved security and UV reduction preventing furniture fading.
    Tinted anti-sun glass: Reducing solar gain, available in blue, green, grey or bronze.
    Neutral anti-sun glass: Neutral in colour with reflective properties to reduce solar gain.
    Self-cleaning glass: Reduces the need to clean the glass, very useful in roofs.
    Obscure glass: Our satin deco is a stylish solution for areas requiring privacy.
    Low-iron glass: Improves the light transmittance through glass while providing some free energy.

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    SUNFLEX SF55s

    Options available: Laminated glass, Tinted anti-sun glass, Neutral anti-sun glass, Self-cleaning glass, Obscure glass and Low-iron glass

    SUNFLEX SF55v

    Options available: Laminated glass, Tinted anti-sun glass, Neutral anti-sun glass, Self-cleaning glass, Obscure glass and Low-iron glass

    SUNFLEX SF75

    Options available: Laminated glass, Tinted anti-sun glass, Neutral anti-sun glass, Self-cleaning glass, Obscure glass and Low-iron glass

    Glass types

    For new-build homes or for change of use projects (barn conversions etc) we fit laminated glass as standard to meet the requirement for P1a glass as specified by Building Regulations Document Q for security. For all other projects (extensions, replacements or renovations etc) we fit toughened glass to comply with Building Regulations Document N.

    Toughened glass
    Toughened glass has been heat tempered to increasing its strength over ordinary annealed glass by up to five times. Other than the strength the advantage of toughened glass is that should it break it would shatter into non-sharp pieces. It is also available with the widest variety of coatings and can be supplied in larger sheets than equivalent thickness laminated glass.

    When the glass is toughened it can suffer from some visual distortion making, meaning the face of the glass is not perfectly flat distorting some reflections.

    Laminated glass
    Laminated glass is manufactured by bonding two panes of annealed glass with a clear plastic interlayer. The benefit of laminated glass is that if it’s broken the glass will crack rather than shattering, improving security. In addition, laminated glass reduces bleaching of carpets, curtains and furniture by filtering UV rays that would usually penetrate the glass.

    The drawback of laminated glass is that extreme heat or cold can cause invisible defects in the glass to form a crack due to the two panes expanding and contracting independently. As the laminated glass is not toughened is does not suffer from the visual distortion that can occur to toughened glass during the toughening process.

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    SUNFLEX SF55s

    Toughened or laminated glass

    SUNFLEX SF55v

    Toughened or laminated glass

    SUNFLEX SF75

    Toughened or laminated glass

    Composite bifold door photo

    SUNFLEX

    Need a timber finish on the internal side of the doors? See our composite bifold doors