Doors for fitted wardrobes can be almost any size or shape you like, subject to certain physical limitations or aesthetics looks requirements. Let me explain further…
If we are talking about hinged doors then the door cannot be too wide and we suggest that this is limited to 600mm wide, to avoid excessive strain on the door hinges.
On the aesthetic front and depending upon what is being designed, then we suggest that the door not be too narrow, as it will not only look strange, but it might not be functional. Also, if you are looking to have a built in corner wardrobe, then the door on this needs to be at least 400-500mm wide, simply to make it usable and to provide access to your clothes.
On a sliding door wardrobe the width of the door can be a lot wider and can be over a metre wide. Normally, the widest suggested door is around 1200mm, as anything larger than this might not look right and makes it very difficult for the fitters to manage.
A sliding door should probably not be much smaller than around 600mm wide, as this would look extremely tall and narrow and aesthetically not pleasing to the eye.
The benefit of fitted furniture over flat pack furniture or flat packed furniture) at places like Ikea or B & Q, where the furniture units are fixed in size, is that it can be any size you like and be designed to fit your home space.