Where possible we would usually install a roller door on the back of or ‘behind’ the opening. This allows the full width and height of the opening to be available as drive through space. There needs to be enough room above the opening to accommodate the roller door drum and roll, usually 300mm, and enough width on the back of the opening to allow for the guides to be fitted. It is possible to install a roller door in between the opening but this means that the drum is positioned in between the opening at the top, which will reduce the height and width available.