Choosing Patio Doors: Why Select Bifolds Over Sliding or French?

A patio just isn’t a patio without a suitably impressive set of doors leading to the interior of your home. The best sorts of doors are practical and form a visual centrepiece for your garden. In some cases, they can even break down the barrier between home and garden to create a single cohesive living space.

One variety of patio door that’s garnered significant attention in recent years is the external bifold door. These enormous concertina-style doors can be up to five metres wide, and they’re certain to make a visual impact wherever they’re employed. But what are their benefits compared to more traditional sliding and French doors? Let’s take a look.

External Bifold Doors or Sliding Doors

Sliding doors consist of two or three large glass panels, each of which moves in a straight line along a fixed plane.


bifolding doors are able to collapse into a much smaller horizontal space than sliding doors, which cannot collapse into a space smaller than a single panel. It’s thus possible to open up a set of folding doors much further than you could a set a sliding ones.

With that said, sliding doors don’t expand outwards as they open, and thus you won’t need to clear any space to either side of the door to use one. While it is possible to achieve a sliding door that effectively disappears when closed, this involves carving a suitable gap into the surrounding wall to conceal it, which means considerable structural work.


If you’re wondering what bifold doors will cost and whether they’re out of your price range, here’s the answer. It costs more to engineer and manufacture a folding door than it does a sliding one. But this difference is minor; you can expect to pay roughly the same for both sorts of door. Your choice of frame material will exert a more significant influence on the final bill. Strong aluminium frames command high prices; weak uPVC frames command lower ones.


Homeowners looking for a truly massive door will want to opt for a bifold door. This is because the cost of glass increases dramatically once the panels exceed a certain size due to large single panes of glass being more difficult to manufacture to a high standard. While a five-metre-wide folding door can be built from six or seven slimline panels, a sliding door is largely restricted to just three, since adding more would make the door impractically thick. As such, if you’ve got a big space to fill, bifold doors beat sliding ones.


How secure are bifold doors? A high-quality bifold door setup will offer just the same security as its sliding equivalent. Reputable manufacturers will include insurance-backed locks with a five-lever cylinder as standard. The cylinder of the lock is often the most vulnerable point of the door; it should be sturdy and resistant to attack from a chisel, hammer or power-drill.

A secondary security concern should be the dressing around your bifold doors. Their expanding nature makes them a poor match for curtains. Invest in high-quality blinds and ensure that would-be intruders can’t see into your property at night-time.


A large patio door represents a considerable amount of weight. If you’re just nipping in and out of the house, then the effort of opening yours might not seem worthwhile. This is where bifold doors are at a slight advantage, as they can incorporate smaller, supplementary doors called traffic doors. If you don’t have another means of accessing the garden nearby, then this can come in especially handy – bifolds which incorporate them are described as ‘x+1’, where x is the number of panels.

Thermal Efficiency

Given that doors of this sort act as enormous windows when closed, we’ll need to bear in mind their ability to retain heat. Aluminium conducts heat far more effectively than double-glazed glass, and thus it’s often the frames rather than the glazing itself that represents the point of weakness. Given that folding doors require marginally chunkier frames than sliding ones, you can expect them to offer slightly inferior thermal efficiency. Having said that, timber and uPVC panels act as superior insulators, and many aluminium ones come with special composite interiors. It’s therefore worth looking into the precise U-values of each door you’re considering before making a final decision.

Sliding doors, by definition, must be able to slide back and forth. This prevents the weather-stripping from being squeezed against the door. Moreover, as the door is moved backwards and forwards over the years, the weatherstripping will wear down, allowing cold air to get in. To ensure the thermal efficiency of a sliding door in the long-term, you’ll need to replace the stripping periodically.


To summarise, bifold doors can be made much larger than sliding ones, and they can fold into a much smaller space. They’re also more resistant to draughts, as their weatherstripping provides a tight seal around the edges when the door is closed. bifolds also look fantastic and are certain to provide your home with that all-important ‘wow’ factor. With that said, you can expect to pay a little bit more for bifolds than you might sliding doors.

External Bifold Doors or French Doors

If your patio needs something simple, affordable and classic, then a set of French doors is certain to appeal. This is a pair of heavily-glazed doors attached to opposite sides of a single frame, so that they meet in the middle. Doors of this sort were first introduced onto the balconies of French aristocrats, who wanted a means of looking out onto their gardens during winter. They’re able to inject just the same sense of grandeur into a British patio, too.

The question remains: are bifold doors better than French doors? Let’s find out!


French doors, containing fewer moving parts than bifold ones, command a substantially lower price tag. They’re also easier to maintain, as they come with fewer hinges and lack a track. Budget-conscious homeowners might therefore prefer them, even before accounting for the cost of modifying the surrounding walls to accommodate a larger door.


Bifolds naturally make a better match for larger living spaces where you’d like to maximise natural light exposure. They can be made five metres wide or even longer and can consist of as many panels as your needs require.

French doors, by contrast, can only be as wide as two panels. While it’s possible to get panels that are much wider than a single standard door, we can only go so far with this before it becomes impractical. This downside can be offset to some extent by supplementing a set of French doors with sidelights – windows that sit on either side of the door, effectively making it look bigger and increasing the total area of glass.


Bifold and French doors are comparable in terms of security. They should both be secured to the surrounding frame. The two panels which form a French door are joined to one another – and this is where they’re most vulnerable to attack. As such, you’ll want to use a three-point locking mechanism and sufficiently sizeable screws (consider three inches a minimum).

You might suspect that glazing would be a major point of vulnerability for a set of patio doors – and that since bifolds incorporate more of it, they’re easier to bypass. This isn’t the case. For one thing, criminals will hesitate before smashing glass, since doing so will cause an almighty racket, and leave all sorts of forensic evidence behind that will make prosecution that much easier. With three separate locks to overcome at various points around the door, the intruder will need to do three times as much glass-smashing. All but the most determined criminal will be deterred!


French doors can be easily opened with a single motion – you might even be able to do it while standing still. As such, they make it easy to access the exterior of your property (and close the door behind you.)

Thermal Efficiency

Being smaller, French doors will allow less heat to escape than larger folding ones. They also tend to come with less glass, which can often mean less heat escaping – particularly if the frames are equipped with a thermal break. With that said, your choice of material will tend to make a bigger difference to the door’s heat-retaining abilities than the style of door itself.


French doors are simpler in construction that bifold ones and are ideal for smaller rooms where a large bifold might be overwhelming. Moreover, French doors are unlikely to ever go out of style; they’ve been consistently popular for several centuries and show no sign of running out of steam!

With that said, Bifold doors make a much better match for larger wall-spaces, and they’re much better able to open up your home onto your patio. What’s more, they form a point of visual interest which other technologies can’t match!


Despite their newfound popularity, bifolds haven’t yet consigned their sliding and French counterparts to the scrapheap. There are still some situations where sliding and French doors do the job better.

Generally speaking, if you have a smaller space and a limited budget, then a compact French door might make a better match for your home. You’ll be able to take the savings you make and use them to invest in more expensive materials, like timber. On the other hand, if you’d like a door that doesn’t expand or swing outwards as it’s being opened or closed, a sliding door is sure to appeal. However, if you have a larger space you’d like to open up, want to make a statement and enjoy a seamless transition between your indoor and outdoor space, an external bifold door is a sure winner. Of course, this is a decision where your personal preference will play a big role – if you’ve weighed up all the pros and cons and you’re still unsure, go with your gut!