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Non-thermally broken aluminium bifold doors - available with single or double glazing

Our SUNFLEX SF45 aluminium bifold doors are the ideal product for use as an internal room divider. Allowing open-plan spaces to be easily opened or closed, reducing sound transmission between rooms or combatting kitchen smells spreading around open plan areas. Bespoke panels can be made up to 1,100mm wide are fitted with a flush track for a seamless floor detail.

Key features

  • Narrow sight-lines just 115mm to maximise light.
  • Secured by Design award. Designed and installed to police preferred specification.
  • Triple gasket seal between doors for finger cushioning.
  • Full range of colour finishes and opening variations.
  • Easy and smooth operation.
  • Concealed ball-bearing running carriages running proud within track to prevent debris fouling the operation.
  • Handle and locking options.
  • Full installation service available.

Versatility in design

The aluminium bifold doors can be folded to the left or the right, and can be opened to the inside or outside. And may have panels all folding the same way or split with a number folding to each side. Whenever an odd configuration is used, one panel is able to open as a single door allowing access without opening more than one panel.

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Whatever your requirements our bespoke range of bifold doors can provide the solution. All systems can open either to the inside or the outside with panels opening to the left or the right. With all bifold door systems an odd configuration will provide a single access door, which can stack the same direction or to the opposite side.

In bifold situations two panels will easily open together allowing access between spaces. Once fully open panels will stack neatly at 90o, all to one side or split with a number of panels to the left and right. With our unique stacking catch the doors will then hold themselves open meaning doors will not start to close if there is any breeze.

Our systems are also available with fixed or moveable 90o or 135o angled corner posts making it possible to completely open up corners, bays or even segmented radius curves.


Standard aluminium finishes

As standard we offer the choice of the five colours, silver anodised EV1; white RAL 9016; silver RAL 9006; grey aluminium RAL 9007; or anthracite grey RAL 7016, as shown below. These colours offer our shortest lead times and are included within our quotations. Once we have prepared a quotation we are able to send colour samples for approval prior to progressing with your order.

Standard finishes for the SF50 bifolding door by IDSystems


Special RAL colours

Over our standard range we are also able to offer the full RAL classic colour range. The range consists of over 200 colours which come in a matt, semi-gloss or full-gloss finish. The colours shown in the swatch will give an indication to the colour shade, however before progressing with an order we can provide aluminium samples for your approval.

RAL colours for the SF50 bifolding door by IDSystems



RAL swatches for the SF50 bifolding door by IDSystems

RAL swatches

RAL classic colour swatches can be purchased directly from us for £10.99 (including postage).

The full colour swatch is a great tool to allow you to choose the colour of your doors and windows to complement your internal decoration, external render, brickwork or other features within your project.

To order a RAL swatch you can make a card payment over the phone by calling us on 01603 408804. If you have narrowed down your choice we are able to send a colour sample for your approval when placing an order.

Glass options

As standard all of our products will be fitted with glazing that exceeds Building Regulations Document N and L which govern safety and thermal efficiency. Over our standard glass there are many options for you to choose from including:

  • 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. 



Download | Aluminium Bifold Door brochure


All systems are made to measure and can be manufactured with panels up to 1,100mm wide and up to 3,500mm high. The maximum height is dependent on the panel width.

However we can always look at a project on an individual basis. Please see panel size diagram or contact our technical department for advice.


The Sunflex SF45 bifold door profile is constructed from a strong light-weight aluminium extrusion with a contemporary square edge profile. When closed the vertical junction between each pane of glass is just 115mm wide making it one of the slimmest systems available.

Track options

There are three choices of track; a standard weathered track for a severe weather rated system, a flush track recessed into the floor, and a low threshold track that sits between the two. The flush track complies with Building Regulations Document M for disabled access and is without guarantee against wind and water penetration.

Weathered track

In any exposed location we would always recommend the use of a weathered track. When used with an outward opening door a weathered track can be fully recessed below your internal floor level meaning that there is no threshold to trip over, just a 35mm step down to the outside. An external deck or paving can be brought up to the track on the outside giving a very minimal difference in levels whilst maintaining a weather tight seal.

Flush track

The flush track option is recessed into the floor, providing an uninterrupted floor finish. Between the door and the flush track are double, twin nylon brush piles incorporating a fin seal, which close the gap effectively. It is recommended that some form of drainage and a slope away from the doors are integrated.

Low threshold track

Sitting between the two above options the low threshold track can be recessed into the floor with matching inside and outside floor levels and just a small 14mm upstand on the track. The upstand allows the doors to form a seal, creating a weather performance superior to flush track.

Download track options (ZIP file 2.07MB)


Although the system is designed to be used internally it is fitted with the same high security features as our external doors although key-locking may not be required.

Any single opening lead door has two alternate options. The system can either be fitted with multi-point shootbolt locking device which is easily opened and closed via a rotation of the stylish handle. With this option the handle remains vertical in-line with the frame when closed not encroaching across the glass. The alternate option is to fit the multi-point lock mechanism with a convenient central latch position. This is similar to conventional door locking, where the door can simply be pushed closed. To secure the door the handle turns upwards and springs back to the horizontal position.

All intermediate positions are fitted with Sunflex flush fitting handles which drive a shootbolt mechanism. The flush design of the handle allows panels to stack tightly together without causing damage to the handles, locks or framework. A key-lock can be added to intermediate positions for increased internal security.

The 20mm wide shootbolt rods are a solid cast metal and are linked to the lock via a steel rod. In addition they are sleeved with a nylon capping to prevent any damage to the track if the door is mistakenly closed with the lock engaged. The wide design and large distance of travel, not only offer a very secure lock, but also compress the panels tight against the top and bottom seals to eliminate drafts. The system can also be fitted with egress furniture allowing the system to open as a fire escape.

Other furniture options include overhead door closers and commercial push/pull furniture, please contact us for further information.

Operating system

The unique Sunflex running gear is mounted to the door profile rather than the hinge that all other systems on the market offer. This gives a much neater appearance negating the need for bulky running gear brackets and hinges whilst improving security.

The stainless steel running mechanism consists of four wheels, manufactured from tough glass fibre reinforced polyamide. And set around a maintenance-free sealed ball-bearing, giving a quiet and smooth operation. Each wheel and guide mechanism can carry up to 200kg which equates over 6m2 of glass.

The wheels of the running mechanism run in a channel in the sides of the track rather than sitting directly on the bottom. Unlike many inferior systems, this minimises the risk of the operating system fouling, should any dirt or debris be allowed to build up in the bottom of the track.


Available as standard in silver anodised EV1 or polyester powder coated to a semi-gloss finish white RAL 9016; aluminium RAL 9006; grey aluminium RAL 9007; or anthracite grey RAL 7016. The standard colours are all included within a quotation and offer the quickest lead times.

Sunflex lever handles are fitted as standard to lead doors which are designed to match the appearance of the flush handles which are fitted at intermediate positions. Generally all furniture is colour matched to the frame. However, we are able to offer an alternate stainless steel finish.

The gasket seals between panels are in black and the hinges which are mounted within the seal are available as standard in white RAL 9016 or black RAL 9011. For an additional fee hinges can be coloured to match the framework or in a stainless steel finish.

Other RAL colours are available with over 200 colours to choose from. One can even have a dual colour with different colours to the inside and outside. Different wood grain effects are available for a nominal charge or even a stainless steel finish. In addition you can specify whether a matt, semi-gloss or full-gloss level of paint finish is required.


As standard the system is glazed with 6mm clear toughened single glazing, however double glazing for improved sound insulation can also be incorporated.

IDSystems offer a wide choice of glazing options, including manual or electrical internal venetian or pleated blinds which can be incorporated inside the glazed unit. These are very popular, especially on internally opening systems where curtains are not practical.

U-Values and heat losses

A U-Value is a calculation of the amount of heat lost through a building material. The calculation of U-Values can be quite complex as it is measured as the amount of heat loss through a 1m2 of material for every degree difference in temperature either side of the material. It is indicated in units of watts per square metre per degree Kelvin or W/m2K. The simplest way to approach U-Values is the lower the U-Value the more thermally efficient a product is.

A U-Value of a door or window is calculated by working out by determining the U-Value of the frame and the area of the glass and is then quoted as an overall U-Value. Beware that some manufacturers may just be providing the U-Value of the glass alone which gives a false overall value. All of our systems have been thermally simulated in accordance with CE standards to BS EN ISO 10077. 

Building Regulations approval will be required on all extensions and new builds to which we are able to provide CE data showing compliance. Any replacement works we are able to cover being a member of FENSA and a certificate would be provided on completion of our installation.

Single glazing

Single glazing can be used for internal systems that do not have to meet Document L regulations regarding thermal efficiency.  Single glazing is available in a variety of thicknesses, types and colours. The most popular options on our internal door systems are clear or satin deco which lets through light but offers privacy.

For more information on our huge range of glazing options or for help in specifying the correct glass for your project contact our technical sales department on 01603 408804.

Solar control and the benefits of solar gain

With the standard glass specification retaining as much heat as possible you may wish to consider reducing the heat transfer from outside which is known as solar gain. Solar gain can make glass roofs, conservatories or south facing elevations quite uncomfortable in the height of summer months.

A solar control glass is a glass with a either a special coating or a body tint to reduce the amount of heat entering a building either by reflecting or absorbing heat. Using a solar control glass can reduce the need for air conditioning and blinds. Whilst the solar control glasses are great at reducing the heat they will also reduce light transmittance.

Building control often recognise the benefits of solar gain in modern buildings as large areas of glass will work as a source of free energy during cooler months and increased solar gains are recommended. The use of low-iron glass can increase the heat and light transmittance to provide further solar gains during the autumn and winter months. Many modern designs incorporate overhangs to cast shadows over glazing during the summer combatting the solar gains. Thus allowing solar gains as the sun gets lower in the sky later in the year reducing the need for heating.

Safety glass

When required we fit toughened glass to comply with Building Regulations Document N as an alternate method of compliance we are able to fit laminated glass. Both options have their pros and cons.

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.

Custom designs

As well as offering full height clear glass we can also provide a more traditional style of glazing by incorporating glazing bars, Georgian grids or lead work. Please contact us for further information.

Venetian blinds

We are able to fit 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 can be manually operated with an ingenious magnetic control device or electronically operated via remote control. Please visit our dedicated blinds pages for further information.

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