How to choose between bifolding or sliding doors

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Nick Dardalis

What is the better door for your home, bifolding or sliding doors? Bifolding doors are great for connecting your room to your garden. Sliding doors better for when you want larger panes of glass. There are also other considerations relating to sightlines and everyday usage of these door types helping you choose between bifold or sliding doors.

picture of a large house with bifolding or sliding doors

The advantages of bifolding or sliding doors explained

Both folding and sliding doors have their advantages. However, there are also other considerations aside from the fact that one door folds and the other slides.

Both bifold doors or sliding doors promise a contemporary and aesthetically excellent grand patio door type, whether you’re replacing an old set of doors or deciding on the best door for a new extension.

For the purposes of this article, we focus more on the larger door sizes and it’s here both doors again excel. If you’re replacing existing doors or building smaller openings, it’s worth considering French doors with bifolds and sliders too.

The purpose of a contemporary patio door in today’s property renovation projects is to create a functional, secure and weather-resistant door, but one that also works with the home and how it’s used. As well as this there are functional and design requirements many homeowners now expect. Slim sightlines, achieving a flush and level threshold, energy efficiency and long service life are just some. Both bifolding or sliding doors deliver on these requirements but in different ways.

Understanding the similarities between bifold doors or sliding doors

Modern bifolding or sliding doors all share several important features making the technical aspects of choosing slightly easier. These are:

  • Thermally insulated profiles working with the glass and giving you energy efficient doors
  • High-quality safety glass also with low U-Values
  • Doors tested to the latest security and weather performance standards
  • Quality guarantees
  • A substantial choice of colours

With the technical considerations similar across both door types, you can now focus on the functional and aesthetic considerations.

choosing between bifold doors or sliding doors in a new home
Closed bifold doors always have more visible aluminium.

Choosing a bifold or a sliding patio door based on appearance

Two significant differences between bifolding and sliding doors may also influence which door type is best for you.

The multiple panel nature of bifolding doors means more visible door panels and aluminium profiles as a result. So whilst a bifold fully opens up in the summer, you’ve got smaller glass sizes, and more aluminium with the doors closed most of the year.

Sliding doors differ. No other door provides large glass sizes up to three metres wide or more. The benefit of these large glass sizes is better views to the outside and in some cases one central visible aluminium profile.

Therefore, if large glass panels, more light and a cleaner outlook through the doors matter, sliding doors are best.

The advantage of bifolding doors is in smaller homes and gardens. The fully opening nature creates an illusion of more space so this too may be a consideration.

The other consideration as well as glass sizes and visible aluminium is the thickness of the aluminium itself and especially with closed doors. Sliding doors come with significantly thinner profiles at the door mullions. When the doors are closed and connected sliding door mullions start at 19mm with a quality slimline patio door. Bifolding door mullions are at around 90-120mm with most quality bifold brands. Again, if slim lines matter most, sliding doors are the choice here.

solarlux cero sliding doors in a new extension
When closed, sliding doors, in two or three panels always have fewer visible profiles.

How bifolding doors work and what it means

Bifolding doors start at two panels and go up to eight or even more. The connected nature of these doors means multiple panels all moving together and folding in either one direction or split to fold in both directions.

A bifolding door needs more operations than a sliding door to open fully. You first unlock the master door, then unlock any intermediate doors (the more panels the more intermediate locks you get) then push the panels to the fully folded position.

Any of the current bifolding door brands, whether mid-range or regarded as the top end bifold doors on the market, all work in the same way.

How sliding doors move.

Sliding doors also start at two panels then three, four, five or six.

It’s easy to assume sliding doors just push to the left or the right. And they do. As a result they require fewer operations than a bifolding door. There’s also a lift and slide option for sliding doors, giving an extra touch of functionality.

Bifolding doors have a significantly slimmer track than sliding doors. The more panels you have sliding in one direction the thicker the track needs to be. For new extensions this isn’t an issue, it’s designed into the structural opening. For door replacements, some modification work is required.

Living with bifolding or sliding doors every day

One consideration when choosing bifolding doors or sliding doors is using the doors in the winter months. Sliding doors will need the large panel moving for everyday access to the garden.

Bifolding doors come with a traffic door option where one door panel swings in or out just like a regular door. So it’s worth considering not just how good both doors look fully open on summer days but also how you’ll use these doors every day.

Using the doors daily is even more important where your door is the only access door out to your patio area or garden. This for many is one consideration when deciding which door is best.

solarlux slimmest bifolding doors
The benefit of bifold doors is revealing most of the available opening.

The differences between open bifolding and sliding doors

The appeal around bifolding doors is that a well-designed system creates nearly 90% clear opening with all the door panels folded open.

Sliding doors when fitted with an existing structural opening will give you more than 50% for two panel doors or 66% with three panel doors and all panels sliding to one side.

This is the significant difference opening depending on their design. However, the air door provides benefits during the construction of a new extension. It is now possible to have sliding doors such as air designed with an extended head and track so they can disappear into the wall of a new extension. They can even be designed with a floating corner post, giving two sliding doors that meet in the corner when closed and fully open the extension on two sides when open.

The British weather means that bifolding and sliding doors will remain closed most of the year. The decision on the best door for the home will depend upon the views they provide when closed and the functionality when open.

choosing between bifolding or sliding doors for a new home
Sliding doors always need somewhere to park and don’t give you the full opening.


We have created an at-a-glance guide to help you see the fundamental differences helping you see all the differences when choosing between bifolding or sliding doors.

Both doors will give you a great solution, but choosing between the two depends on your home, your aesthetic preferences and how the doors look closed in winter as well as fully open in the summer.

Considerationsbifolding doorssliding doors
Best foropening up the spacethe very best views
Typical maximum sizeup to 8+ metresup to 12+ metres
Dimensions of vertical mullionsfrom 94mmfrom 19mm
Maximum Panel Widths1.5 metres3 + metres
Maximum Panel Heights3.5 metres3.5+ metres
Low level and flush threshold optionyesyes
Takes up internal/external space when openyesno
Available space when openup to 90%up to 66%
Flush Floor Level InternallyYesyes
Flush Floor Levels ExternallyYesNo
Cornerless solutionyesyes
Doors disappearing into a wallnoyes
Anti-finger trap technologyyesno
Matching single and double doorsyesno
Security Testedyesyes
Low U-Valuesfrom 1.4Wm2Kfrom 1.38Wm2K
Severe Weather Performance.yesyes