If you are planning a kitchen extension or replacing tired old patio doors, you have probably already noticed that bifold and sliding doors are the two main contenders. Both flood a room with light and open your home out to the garden, and both have moved a long way from the doors of even ten years ago. The right choice comes down to how you actually use the space day to day, not which one looks best in a photograph.
This guide walks through the differences that matter once the doors are fitted: how much of the wall actually opens, how easily you can let in a little fresh air, the view you get when the doors are shut, and the practical questions around space, security and cost.
How bifold and sliding doors work
A bifold door is made up of several glazed panels joined by hinges. Push the end panel and the whole set concertinas together, then rolls along a track to stack neatly against one side of the opening.
Sliding doors work on a different principle.
The panels sit on their own tracks and glide past each other, with one section staying fixed while another slides behind or in front of it. There is no folding involved, and that difference in movement is behind most of the practical differences below.
“There is no wrong answer between a bi-fold and a sliding door, only the wrong one for your garden. We will always tell you honestly which suits the space, not which one we would rather sell you.” John Flynn, founder
How much of the opening actually opens
This is usually the deciding factor for anyone planning a big kitchen-diner extension.
A bifold door can open up almost the entire width of the wall, so the room and the garden genuinely become one space.
A sliding door opens a smaller share of the total width, because at least one panel always has to stay in place to give the others somewhere to slide behind.
If you want the wall to disappear completely on a summer afternoon, a bi-fold door does that better than a sliding door ever will. If a wide, generous opening suits you better than a fully open wall, sliding doors do the job very well too.
It is worth walking the space and picturing both before you decide.
Letting in a little air
Not every day calls for the doors to be wide open, and this is where sliding doors have the edge. Slide one panel open just enough to take the stuffiness out of a room, then push it shut again in seconds.
A bifold door can do this too, though it depends on the design.
On some configurations, opening even one leaf means unlocking and folding back several panels next to it. A single small opening for ventilation becomes more of a job. Ask us about traffic doors, covered below, if quick day to day access matters to you.
The view when the doors are closed
Sliding doors tend to win here. Because the panels only need to slide rather than fold, they can be made in larger, wider sections held together by slim uprights called interlockers.
Fewer frames breaking up the glass means a clearer, more uninterrupted view of the garden.
A bifold door carries more framing by design, since every panel needs its own set of hinges.
That is not really a drawback. A run of narrower panels has an architectural quality of its own, while a sliding door reads as one continuous window. Both look excellent; it comes down to what you want to see from the sofa.
Configuration: which way should the doors stack?
Bifold doors can stack entirely to one side, or split so that some panels fold left and some fold right. Because of this they can be referred to as concertina doors.
Either way, the stacked panels need clear space to sit in once open. Think about what lives nearby: furniture, planters and barbecues all need to stay clear of that spot.
Where the number of panels allows it, we would usually recommend a traffic door.
This is a single panel that opens on its own, like an ordinary back door, without unlocking the rest of the run.
It sounds like a small detail, but it changes how often the doors actually get used. Popping out to the bin or letting the dog into the garden no longer means opening the whole wall.
The threshold question
Every glossy photo of a bifolding door shows a flush threshold, with the floor running straight out to the patio and no step to cross. It is achievable, but it comes with a trade-off worth knowing about before you choose it.
A low, flush threshold looks superb and suits wheelchair or pushchair access well.
It offers less resistance to wind-driven rain than a raised one. A slightly higher, weathered threshold copes far better with an exposed garden and heavy weather, at the cost of a small step. Most homeowners settle on something between the two, and we will talk you through which suits your garden and how sheltered it is.
Are bifold and sliding doors secure?
Both door types are built to recognised UK security standards, with multi-point locking that engages at several points around the frame rather than at the handle alone. Anti-lift devices on the track stop the door being levered out of its frame, which was a known weak point on some older sliding doors.
Aluminium is a naturally strong material, and that helps both door types resist forcing at the frame itself. If security is a particular concern for your home, ask us about the options when we come to survey your opening.
What do bifold and sliding doors cost?
There is no single answer, because price depends on the size of the opening, the number of panels, the configuration and the glass specification, among other things.
A modest two-panel sliding door for a small patio and a wide six-panel bifold across an open-plan extension sit at very different points on the scale.
The only reliable way to know is to have us measure your opening and talk through what you want from the doors.
Call us on (020) 8868 1133 for a free, no-obligation quotation, and we will give you a clear price based on what is actually going into your opening.
Which is right for your home?
If your priority is opening the room to the garden completely, for entertaining or a big open-plan kitchen-diner, a bifold door is usually the better fit.
If you want a wide, uninterrupted view and the flexibility to crack the doors open on a cooler day without a fuss, lean towards sliding.
Plenty of homes end up choosing on the practicalities of the space itself: a narrower patio with furniture nearby often suits sliding doors better, while a wide, clear opening on a rear extension gives a bifold door room to do what it does best.
Come and see them for yourself
Both are far easier to choose between with the doors in front of you.
Our showroom at Unit 34 Orbital 25, Dwight Road, Watford has bifold and sliding doors set up side by side, so you can open and close both and see exactly what we mean about the threshold, the view and the traffic door.
We fit bifold doors from Origin, including the steel-look Soho Collection for a more industrial finish, and sliding doors from Smarts using their Visoglide system. Both can be specified with integral blinds sealed inside the glass itself, giving you privacy and shade with nothing to dust and nothing hanging in the way.
Ruislip Windows has been family run since 1986, covering Middlesex, Hertfordshire, Buckinghamshire and the surrounding areas. We are FENSA and CERTASS registered, our work is covered by insurance-backed warranties through QANW, and our lead time from order to installation is normally three to four weeks.
There is no hard sell, and never has been.
Call us on 020 8868 1133 for a free, no-obligation quotation, or come and see us in Watford.