Strange door sizes

838 doors can be adjusted to the correct size, provided they are solid core doors. This is done by removing the lipping, removing the redundant section and reattaching the lipping to give it back its proper edge. This is more labour intensive than materials so will usually cost more than a simple door hanging

You don't necessarily need made-to-measure doors or to alter your existing frames. An 800mm doorway is an awkward size, but there are cheaper ways around it. The main thing is to establish whether 800mm is the actual width between the door frame rebates (where the door sits) or the width of the opening itself. Your options 1. Buy an 838mm door and trim it down. You'd need to remove 38mm in total, approximately 19mm from each side. If the manufacturer only permits 16mm per side, that's 6mm beyond the total permitted trimming allowance. I wouldn't recommend exceeding it, particularly on hollow-core doors. 2. Look for a solid-core or solid timber door. Some can be trimmed more extensively, depending on their construction and the manufacturer's instructions. This could avoid modifying your frames. 3. Consider a 762mm door. It's a standard UK size, but it would leave a 38mm difference. You could potentially make this work with timber extension strips, although this would involve modifying the frame or door arrangement and may not look as neat.