Velux location in new bedroom

I'm adding a new bedroom to our dormer bungalow by splitting an existing very large bedroom.

The new bedroom will have a large velux and I'm trying to decide where it should be located.

Does anyone know what is the maximum distance that the base of the velux should be from the flooor so that it complies with building/fire regs.

The door of thenew bedroom will open into the landing/ stairs area.

There are other existing velux windows in the same roof area and ideally I would like to have the new velux at the same height as this would look best from outside.

I would like to be armed with this knowledge when I speak to the builders so any comments or help would be great.
Thanks.