The bi-fold door works through a combination of glazed panels hinged at the side and track rollers. The first panel folds outwards like a door and magnetically clips to the second panel. The subsequent panels are hinged on opposite sides so that the doors fold in a concertina effect. At the top and bottom of the panels are rollers that slide along tracks in the floor and ceiling so that the folded doors easily glide to one side and stack as flat as possible at the side.

One of the panels can be used as a convenient door that can be opened independently, or all panels can be folded back to fully open up the space.

Everest bi-fold doors can be configured in a variety of ways. Either to open from one side, sliding across to the other side. Or, they can open from the centre and fold outwards to each side, left and right.

Most homeowners opt to have doors that open outwards, but doors can be configured to open inwards or outwards.

The majority of bi-fold doors are designed with a key locking multi-point locking system as well as a hidden inline tracking system. This makes it almost impossible for a burglar to lift the bi-fold doors out of their mechanism.

Everest bi-fold doors feature steel shoot bolts at the top and bottom of the frame. They also have multi-point locking on external opening doors. Locks are Yale 3*** Euro Cylinder which meets British Safety Standards. The locks also have a 10 year guarantee for extra peace of mind.

Choosing between traditional sliding doors and bi-fold doors depends on what your needs are.

The main benefit of bi-fold doors is to create a seamless space between inside and outside. When open, bi-fold doors add the wow factor to a property and can add value to your home.

If you have limited space, sliding patio doors might be the better option.

Bi-fold doors can have between two and seven panels to cover a space up to 6,420mm wide and 2500mm tall.

Bi-fold doors are covered under permitted development rights. That said, in some areas planning permission may be required (for example, conservation areas), so it is always advised to check with your local authority which Everest can help advise on. As a rule, if you are altering a door opening or installing bi-fold doors, you will need to ensure the existing opening is capable of withstanding the extra weight and may require a building notice.

Read more: Do you need planning permission for doors...

Bi-fold doors tend to be more expensive as they have more moving parts and complex elements such as running tracks. Whereas, sliding doors are simpler in their design and as a result tend to be cheaper.