Bifolding Door Sizes; what to consider

Bifolding doors provide an excellent solution for new extensions as well as replacing older patio doors.  The range of bifolding door sizes available means that there is no such thing as a standard size.  So a bifolding door can be made to fit almost anything from a tradition french door opening through to the largest folding glass walls.

Bifolding doors, therefore, provide great flexibility and functionality, enabling most houses to benefit from these popular types of doors.  We explain some of the important things around bifolding door sizes.

bifolding door sizes
SUNFLEX is one high quality system with panels up to 3.5 metres high.

Understanding bifolding door sizes.

Most bifolding doors come with minimum panel sizes from 400mm wide.  The maximum panel width varies with each product. Typically maximum sizes go up to about 1200mm wide. For the bifolding door heights, most brands accommodate standard and taller openings.  Some bifolding doors such as SUNFLEX go up to 3.5 metres high to meet a need for even bigger doors.

With most bifolding doors allowing up to seven leaves (with more possible), many different configurations exist.  Door panels slide to the left or the right, as well as an equal or unequal split.

Study the various bifold door systems, and you see how the number of panels provides different ways to slide and fold.  The number of panels also affects bifolding door sizes.

The panel width you choose determines the number of door panels. Most bifolding doors go up to at least 1 metre wide per panel, with others better engineered for wider panels.

The bifolding door brand may dictate the design.

Another consideration is whether your choice of bifold determines the overall configuration. Again this is largely down to the door panel sizes. For instance:

A four-metre door opening with door panels at 1metre width naturally gives you four panels.  If you choose a brand with door panels up to 1350mm, you only need three panels.  Three panels mean less visible mullions, bigger doors and, of course, bigger glass.

A 3.6-metre wide door opening requires four panels with a system offering leaves up to 1000mm. Choose a 1200mm wide panel and again benefit from only three panels. And remember the fewer door panels, the cheaper the bifold door.

Another consideration when thinking about bifolding door sizes is the space taken with the panels open and folded back.  A 1200mm door undoubtedly provides bigger glass and better views with the doors closed. However, they will take up a lot of space folded together. This especially applies if you want your doors to fold into the room and not out onto the patio.

Bifolding door panel sizes compared.

Most of the popular and cheaper systems like the Visofold 1000 bifolding door or the Aluk Optio offer panels up to 1000mm wide. This size is perfectly adequate for most projects and bifolding door sizes.  The premium and better-engineered doors are the ones going wider and taller.  Size capability with bifold door systems is a good indicator of their overall quality and engineering too.

Take a look at some of the well-known brands to see the panel sizes offered.

 Maximum WidthMaximum Height
Visofold 60001000mm2200mm
Visofold 10001200mm2500mm
Aluk Optio BSF701000mm3000mm
Alumina by Liniar1200mm2500mm
Origin Bifoling Door1200mm2700mm
Schuco ASS70FD1200mm3000mm
Duteman FD851350mm3000mm
SUNFLEX SF55e1200mm3000mm
SUNFLEX SF551200mm3500mm
Alufold Warmcore1250mm2500mm
Reynaers CF771200mm3000mm
SUNFLEX SF751100mm3500mm
Reynaers CF681000mm2500mm
Air 8001200mm3000mm

Importantly, many of the sizes shown with these popular quality brands are for guidance only. Not every system allows you to have their door at the maximum width with the maximum height.  Often a wider or panels mean less on the height.  Check with your supplier or contact us for help and advice.

Finally, the bigger the panel, the fewer doors and fewer visible mullions. As a result, you get a six-metre door with only five panels as a further example.

Floating Mullions on Bifolding Doors.

If you desire an even number of door panels (2, 4, or 6) all sliding/folding in one direction, many brands must come with a floating mullion. The floating mullion adds an extra aluminium profile and sight line to the locking side of the door. As a result, the closed door set can look uneven, especially on a two panel bifold.  The floating mullion on even number doors presents the door gear from hitting the side frame when the doors close.

You won’t need a floating million on an even number of doors (4 or 6) where they are split. For instance a four panel door with one door opening to the left and three to the right.

French doors in Aluminium.
Bifolding door sizes for smaller openings.

Many new build homes, as well as older properties, feature a French door or two panel sliding door at the back of the house.  Is it worth having a bifolding door in these apertures intended for French Doors?  There are pros and cons to replacing French doors with a two or three panel bifolding door.

Two panel doors can only fold in one direction. This may not be convenient if this is the only door at the back of the house and you use it often.  Consider a three panel bifold.  You get the traffic door but much smaller door panels.

If you do have a traffic door, consider hanging it on the adjacent leaf. As a result, your doors fully open to the one side which works much better.  The floating mullion is necessary on a two panel door too.

Finally, consider privacy and shade.

With all bifolding doors for large openings comes issues with heat, light and shade. This is especially true for elevations in direct sunlight.

Integral glass blinds provide a great solution but add to the cost.  Integral blinds work particularly well with bigger bifolding door sizes.  The benefit of integral blinds is no cleaning, blowing in the wind and a discreet blind housed between the glass of your doors.  We recommend visiting a good showroom and seeing integral blinds in action. They also come as motorised or solar-controlled and in many different colours too.

Our top tips for getting your bifolding door sizes right.

  • Always talk to a professional installer and avoid a builder fitting the doors. You also get a better guarantee when supplied and installed.
  • The wider the door panel, the fewer visible mullions with bigger door glass.
  • Consider the benefits of a traffic or lead door.
  • An odd number of door panels gives you a more flexible bifold door.
  • Ensure the large doors have premium handles. The more panels, the more internal handles you get.
  • Doors over six metres may have joints in the frame.
  • Consider one of the premium brands above the cheaper systems.

Need more help and where to buy? Contact us today.

Every year we help thousands of homeowners, answering their questions, suggesting the right products and helping them get in touch with the right suppliers.  Contact us for free, independent and impartial advice.

Reader Interactions


  1. Debbie Coate says

    We have a space measuring 3.6m x 2.1 and want bi folds with a traffic door to use as our back door. We have young kids and are concerned about having a big heavy door. Do you have any tips and what do you think the best configuration would be based on our measurement? Many thanks.

  2. Helen Goodall says

    Can you tell me what the width of the mullions are on an aluminium bifold door. My father is anxious not to spoil his wonderful view.

    • Nick Dardalis says

      Hello Helen. Mullion sizes depend on the product ranging from about 94mm with the Visofold 6000 door, 99mm with Solarlux and these are the two slimmest. So do get in touch via our contact form and I can suggest some brands and systems as well as installers to get in touch with.

      Hope this helps
      Kind regards,

    • Nick Dardalis says

      Hi Jamie, depending on the product and it’s level of weather performance, quite well.
      Origin doors for instance are hurricane tested for the US market, but most well fitted and made products should give you good performance in a windy location.

  3. Simon Neill says

    I am interested in fitting two sets of high quality (Schuco or equivalent) bifold and some sliding doors. I live near Bath on the Wiltshire/Gloucester border. Please could you recommend some suppliers?

    Many thanks

    • Nick Dardalis says

      Hello Simon, if you’d like to get in touch via our contact form we can assist you further with this and suggest some suppliers

      • Nick Dardalis says

        Hello Simon

        Due to the increasing volume of comments, we are struggling to manage these via the comment forms. Therefore, please can you use our contact form where these are managed and always responded to.

        Kind regards

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