If you've typed bi-fold doors vs patio doors into a search bar, you're probably looking at a wide opening at the back of the house. Both let in plenty of light. Bi-fold doors fold back to open most of the gap, while sliding patio doors run past each other on a track and keep more glass in view. We're Exterior Plas, a family run manufacturer founded in 1988, and we make and fit doors from our factory and showroom in Thornwood, Epping. Here are the honest trade offs.
Key takeaways
– Bi-fold doors open more of the aperture, because the panels fold and stack to the side, or to both sides.
– Sliders look cleaner when they're closed.
– Doors in the UK stay shut for much of the year, so the closed view matters more than most people expect.
– Bi-fold doors need room for the folded stack. Sliders don't.
How bi-fold and sliding patio doors differ
The real difference is how the panels move: bi-fold doors fold up like a concertina and stack to the side, while sliding patio doors run along a track, each panel passing the next. Everything else follows.
Because a bi-fold set folds away, you can open nearly the whole width of the frame and step straight out, with nothing left standing in the gap. Sliders can't. At least 1 panel always sits in the opening, so a 2 panel slider usually opens about half the width. Homebuilding & Renovating's comparison of bi-fold and sliding doors sets out the same basic trade off, with bi-fold doors ahead on open width and sliders ahead on glass area.
Here's how they compare on the 4 points that matter most.
| Feature | Bi-fold doors | Sliding patio doors |
|—|—|—|
| Opening width | Most of the aperture opens, as panels fold and stack to the side | Part of the aperture opens, as at least 1 panel stays in the frame |
| View when closed | More vertical frames where the panels meet | Fewer, larger panes and a cleaner view |
| Space needed | Clear floor or patio space for the folded stack | No swing space, as panels stay within the frame line |
| Moving parts | More hinges, rollers and locking points across several panels | Fewer moving parts, mainly rollers running on a track |
Which suits UK weather and everyday use
For most UK homes, the closed view matters on more days than the open view, which tends to favour sliders on looks, though bi-fold doors earn their place if you use the garden often.
Think about your year. On a warm Saturday in July, a fully open bi-fold set joins the kitchen and patio into a single space, and on days like that it's hard to beat. In a grey, wet February, those same doors stay shut, and you'll spend weeks on end looking out through the frames where each pair of panels meets. A slider gives you bigger panes on those days, so you lose some open width in summer but get a calmer view for the rest of the year.
If you're in and out of the garden all day, many bi-fold sets can include a traffic door, which is a single panel that opens like a normal door. That way you don't have to fold the whole set just to put the bins out. Sliders can open a little way for air and won't catch the wind like an open door.
Then there's space. Folded bi-fold panels need somewhere to sit, so if a step or a planter is right outside the doors, check the stack will clear it before you commit.
The materials we work with
The material shapes how slim the frames look as much as the door style does, and we manufacture and install doors in aluminium, uPVC and timber. Aluminium is a common pick for wide glazed doors because it's strong enough for slimmer frames, which helps calm the busier look of a closed bi-fold set. You'll find that range on our aluminium doors page. uPVC suits many homes. Timber fits period properties, or anyone who's after a natural finish.
We manufacture and install bi-fold doors made to measure for each opening, so the panel count and configuration are set around your space. Our factory in Thornwood uses CNC machinery and fabricates REHAU systems, so we're in control of the work from the first cut to the final fitting. Our doors page shows the full range we supply.
When bi-fold doors are not the right choice
Bi-fold doors aren't right for every opening, and in the 4 cases below we'd suggest thinking twice or looking at a slider alongside them.
– Narrow openings. Across a short width, several panels and their frames can eat into the glass, and another door type often looks better.
– Tight outdoor space. If the patio is small or steps sit close to the doors, the folded stack may get in the way every time you open them fully.
– You mostly want a picture window. If the doors will stay shut most of the year and the view is the whole point, a slider's bigger panes may suit you better than a folding set.
– You'd prefer fewer moving parts. Bi-fold doors have more hinges, rollers and locks to keep clean and adjusted.
If opening the full width matters most, though, a slider will always leave at least 1 panel in the way, and that's when a bi-fold set makes sense. Get in touch for a free quote if you're still weighing it up.
FAQs
Are bi-fold doors better than patio doors?
Neither is better across the board. Bi-fold doors open more of the aperture, while sliding patio doors give a cleaner view when closed, so the right pick comes down to your opening and how often the doors will be open.
Do bi-fold doors let in less light than sliding doors?
They can, slightly, when they're closed. The extra vertical frames where the panels meet take up some glass. Slimmer aluminium frames help.
Which patio doors suit UK homes best?
That depends on the house and how you'll use it. Many UK homes keep their doors shut for much of the year, so the closed view counts for a lot, and that often points towards a slider. If you're out in the garden a lot over summer, a bi-fold set's full opening can make up for the busier view in winter.
Can you tell me how much bi-fold doors cost?
We don't publish prices, because every door is made to measure. Once we know the size and material we can give you a free quote, so call us on 01992 578 903 or visit our Thornwood showroom, Monday to Friday, 9am to 5pm.