Generally speaking, it will take 1 or 2 engineers around 3-4 hours to fit your new composite door.
Composite doors are constructed from GRP (Glass Reinforced Plastic), which is another name for fibreglass. This is an extremely versatile material that has been made to look just like timber. A foam-filled core ensures the door is light, strong and thermally efficient, and the outer layers are scratch and chip resistant. In fact, the colour you choose will be applied throughout the GRP, ensuring that it will not fade or peel in the elements.
Composite doors are practically maintenance-free; all they require is a wipe down with a cloth and soapy water every now and again. You do not need to treat or repaint your door.