Bi-folding doors are a popular choice for commercial buildings providing an indoor-outdoor transition, composed of a series of panels that fold and stack, allowing for full or partial opening, providing a wider opening than traditional sliding or hinged doors. They are energy efficient and can come in different materials such as wood, aluminium and PVC, and can be customised to match the aesthetic of the building. They can also be integrated with other systems like locking, security, and automation for added convenience and security.