There has been an increase year on year in the popularity of bi-folds. Customers love the idea of folding/sliding back the doors so that the inside and outside are inter-changeable.
Which style of door to have really does depend on whether your build and design style is contemporary or traditional. If your house is contemporary in style then bi-folds are probably for you, if on the other hand your house and interior style is traditional then French doors would most likely be the route for you.
Bi-fold doors remain hugely popular due to their ability to be folded back thereby completely opening up the interior to the outside. If you consider at an early design stage what flooring you’re going to lay you can use the same tile inside and out to provide a seamless look so that when you’re sitting indoors and look out to the garden, the floor threshold just flows throughout. This visual trick helps you to elongate your living space, especially when the bi-folds are open. If you are lucky enough to have a wide span that is useable for bi-folds then they also come into their own during the Winter as this is a time when it is beneficial to get as much light into the house as possible, natural light that is, not electric. Bi-folds can be quite frame heavy, meaning less glazing, so are probably best suited to large openings.
Stacked or folded panels can also be visually bulky in a small space, again more suited to large openings.
French doors have less glazing than bi-folds but can work very well with sidelights or positioning them within a run of glazing. They do provide a quicker means of access to the garden as you don’t have to fold or slide a whole number of panels open to get outside.
Sliding doors can be less bulky as they have no sections to fold back and can at the design stage be specified in the plans that they slide away into a cavity so that they function as ‘pocket doors’. They are then invisible when open.
There is of course quite a differential in cost, so this may also sway your decision as to which style of door you go for.
Bi-folds on an Arboreta orangery project.
French doors on an Arboreta garden room.