The factory is huge, the team are busy and they just want to make as many sets of Aluminium bifolding doors as they can... Bespoke sized doors, and bespoke colours are not their friends. With each different order they need to take time to set up the machinary, make the necessary cuts, set up more machinary to place the holes and cuts in the appropriate places for the locks and handles.
To counter this they offer us standard sized doors (2400mm wide, 3000mm wide and 4000mm wide) in standard colours (Black, White or Anthracite Grey) to a standard 2100mm door height. These doors can then just be made in batches bringing the manufacture costs down and improving our prices.
In no way are these doors of a lesser quality - they are simply more cost effective to produce