A STANDARD requirement for our lift installation is provision of a raw door opening that is 20mm wider on each side and also above the door frame. This allows some flexibility with the installation and caters for openings slightly out of plumb.
Once the door and frame has been installed, the typical finish that is done is grouting/plastering/rendering in the opening and painting to match elsewhere. However, sometimes other methods are chosen such as tiles/stone, architraves or steel angles.
See some examples of the different finishes.