3-panel bifold doors, made to measure

Where the 2-panel bifold door has no separate traffic door, this one adds one: a panel that swings open as an ordinary door, with the other two panels folding away beside it. For everyday use — nipping outside, letting the dog out — you open just the traffic door; you fold the rest open when you want the full width.

The standard size is 2,800 × 2,300 mm, up to 3.00 m wide. If you need more width, the 4-panel, 5-panel and 6-panel bifold doors are the wider steps up, each with more folding panels beside the door.

The traffic door works no differently from an ordinary garden door: it swings on its own hinges and locks with its own lock, independently of the folding panels beside it. That means you can lock up with just the traffic door shut, without checking the folding panels every time — handy if you lock up in the evening after leaving the set open during the day.

Three metres is the first width in our bifold doors where a separate traffic door really makes a difference: on the 2-panel bifold door (2.05 m) the whole set folds open quickly enough to do without one; from three metres and more panels, folding the whole set for a quick trip outside takes more and more effort, and a separate door becomes the logical addition.

For this bifold door, measure the width and height of the opening, the reveal the stack of folded panels will stand against, and the floor build-up under the track. The traffic door also needs its own threshold detail, just like an ordinary door — have your installer confirm how it meets the floor before you order.

Colour and finish are usually the same across the whole set, traffic door included, so there is no break in the look between the part that swings and the parts that fold. Maintenance is split between two kinds of hardware: the hinges and lock of the traffic door, in use every day, and the folding hinges and bottom track of the two folding panels, which move less often but need to be kept clear of dirt.

When renovating a living-room wall, this is often the replacement for a wider set of French doors, with the advantage that the whole set can open up in good weather instead of the fixed width of two swinging doors. In a new build, this size is often chosen as the first step where a separate traffic door already makes sense, compared with the smaller 2-panel bifold door without one.

For security, the traffic door is comparable to an ordinary door, with its own lock; the folding panels lock through the locking points at each panel joint. Ask about the standard specification of both if the set is going on the ground floor.

The traffic door carries its weight on its own hinges, separate from the folding hinges of the two folding panels. The configurator checks for each panel whether the hardware suits the profile and the size.

Still not sure? Use the comparison with the other layouts in this group, above, to see which arrangement suits your situation best.