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Thermally insulated versifold doors - available with double or triple glazing

The SUNFLEX SF55v versifold door is an innovative new 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, whilst not compromising on the extreme weather performance and U-value that the SUNFLEX range is renowned for.

Developed utilising combined experience of award-winning bifold door technology and industry leading internal slide and turn systems, SUNFLEX has successfully developed the most advanced door of its type on the market - offering complete versatility.

Initially available to complement the SF55 bifold door system, the versifold range of doors will expand to cover our entire range of non-insulated, insulated and highly insulated doors in aluminium, timber and timber/aluminium composite.

Key features

  • Truly versatile stacking technology
  • Revolutionary narrow intermediate sight lines (115mm) maximising light and enhancing your view.
  • Slim front to back profile (55mm) minimising stacking area.
  • Triple gasket for finger cushioning and tight compression seals. The most weather tight bifold doors available.
  • Severely weather rated with weathered track and unbeatable reassuring test results (900Pa water tightness).
  • Mushroom locking into side jamb coupled with top and bottom metal shoot bolt rods, excellent security. WK2 security package available.
  • Secured by Design award. Designed and installed to police preferred specification.

Versatility in design

The system may be folded to the left or the right, open to the inside or outside, and unlike traditional bifold doors can be stacked at either end, centrally or part opened providing more flexibility - particularly for those with space limitations.

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SF55v Technical


Versifold Door Configurations

Whatever your requirements our bespoke range of bifold and versifold 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. 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.


Standard aluminium finishes

As standard we offer the choice of the six colours -Silver Anodised EV1,Traffic White RAL 9016 semi-gloss, White Aluminium RAL 9006 semi-gloss, Grey Aluminium RAL 9007 semi-gloss, Anthracite Grey RAL 7016 semi-gloss, Graphite Black RAL 9011 matt or Slate Grey RAL 7015 matt

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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.


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-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 swatches

RAL classic colour swatches can be purchased directly from us for £10.99. 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 simply and safely press the buy it now button and make a secure payment using your Paypal account or a with a debit/credit card. Alternatively 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




The manufacturer recommends panel widths do not exceed 1100mm and a maximum height of up to 3500mm. Heights greater than this can be achieved, please contact our technical department for advice.


The Sunflex SF55v bifold door profile is constructed from a strong aluminium extrusion. This has been thermally broken by a 24mm polyamide insulation bar, guaranteeing it optimum resistance to combat heat loss and condensation. The minimal framework is offered as square edge profile.

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)


The standard locking system offers a very high level of security with a quick, smooth and easy operation. It consists of a two-point top and bottom shoot bolt mechanism, which is incorporated into the framework within each intermediate panel. For improved security all Sunflex folding door systems are internally glazed as standard with centre secured locking hinge pins and interlocking gaskets.

The lead door features multipoint lock and a five-lever profile cylinder. It can be fitted to either the inside only or both internally and externally, meeting the requirements of the Association of British Insurers.

The shoot bolt rods are manufactured in aluminium and linked by a corrosion resistant cam. In addition they are capped with polyamide cones that prevent any damage to the track when locking, whilst compressing the panels tight against the top and bottom seals.

Throughout the range of Sunflex folding systems you have the option of internal and/or external handles. Handles are fitted to every intermediate door panel and additional locks can be added at these points for higher security.

Weather seals

The system is a severe weather rated system when used with the weathered track option, providing a top and bottom double-rebated seal. Unique triple gaskets provide a finger cushion and eliminate draughts. The system BS EN 12207 air permeability Class 4, water tightness Class 9A (900Pa), wind resistance Class 4.

The triple gasket seals both at the front and the back of the panel are continuous, even behind the hinges, and of superior quality (consisting of long lasting EPDM). The unique design of these triple self-sealing gaskets provides a minimal sightline. Whilst providing a cushion to minimise injury if fingers were to be trapped, in addition to improved weather performance.

Operating system

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, smooth operation with optimum resistance to extreme weather and temperatures fluctuations.

The Sunflex SF55v versifold door can be adjusted to alter height and load of the system to provide a degree of tolerance. 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.


The Sunflex SF55v system is 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.

Single doors fitted as standard with lever handles. With first opening pair and intermediate door panels fitted with flush handles are specially designed to complement the door system. Standard colours are white RAL 9016; black RAL 9011; aluminium RAL 9006; grey aluminium RAL 9007; or anthracite grey RAL 7016. Gaskets are in black, with hinges mounted within seal sightline available in white RAL 9016 or black RAL 9011.

Other RAL colours are available with over 200 colours to choose from. You can even have different colours to the inside and outside (dual colour) or different wood grain effects are available for a nominal charge. The RAL colours can be applied to the handles and hinges if required or alternatively there is a stainless steel handle and hinge option. In addition you can specify whether a matt, semi-gloss or full-gloss level of paint finish is required.

A marine environment finish, required to all systems within 5,000m of a shoreline or chemical swimming pool environment, is also available.


Trickle vents with an airflow equivalent to 2,500mm2 or 5,000mm2 can also be incorporated with the addition of a 35mm add-on head profile. These will be colour coded to suit the frame colour choice.

Pull handles

When the bifold door system opens externally the intermediate panels are fitted with a moulded 'D' shaped handle. This is attached to the internal hinge between two even panels, and sits neatly within the gasket line. This enables easy closure of panels against the compression top and bottom gasket seal.


Designs can be customised according your preference - the options include mid-rails, mullions, plant-on bars with dummy spacer grids, among many others.


The SF55v versifold door system is internally glazed and can accommodate glazing ranging from 4mm clear toughened glass up to a triple glazed sealed unit of up to 36mm.

Our standard 28mm unit comprises of 4mm clear toughened glass with Low-E (low emissivity) to the inner pane x 20mm argon gas cavity x 4mm clear toughened glass. This complies with the Building Regulations for safety and thermal efficiency.

All units are BS kite marked, manufactured to BS EN 12600 and BS 5713:1979 standards.

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 1 square metre 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 EN 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.

Double or triple glazing

Double glazing is a minimum requirement for external doors and windows.  Our standard double glazed units consists of a soft-coat low-e pane and an 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 1.0W/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.

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 unbearable in the height of summer months like stepping into a greenhouse. 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 have an impact on 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 glazing 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 reduing the need for heating.

Safety glass

As standard 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 isn’t perfectly flat distorting some reflections.  Thicker toughened glasses are less susceptible to visual distortion; please contact us for further advice.

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 ultra-violet 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.

Cat flaps

Often neglected when planning your new build or extension is where a suitable space may be for your feline friend, we have the ideal solution.  It is possible to have a cat flap fitted into a glazed panel by cutting a circular hole into the toughened glass unit for you to fit an in-glazed cat flap.

Venetian blinds

We are able to fit Venetian blinds withing 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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