In britain the transom light is usually referred to as a fanlight often with a semi circular shape especially when the window is segmented like the slats of a folding hand fan.
													
																	Window above internal door name. 
									
	
		
	
																	Transom is also the customary u s. 
																	Hi jennyhd you are correct according to websters new world dictionary a transom is a strengthening crossbar or beam in particular one set above a window or door. 
																	In britain the transom above a door is usually referred to as a fanlight and occasionally as an overlight or hopper or by the french word vasistas. 
																	Our friend recently moved into a new house which has glass panels above the internal doors and while she isn t very keen on them her husband actually quite likes them. 
															
													
									
	
		
	
																	So a transom window is a window that is placed above a transom. 
																	Word used for a transom light the window over this crosspiece. 
																	Out of her curiosity she asked me what these over the door windows were and because i was very interested too i decided a spot of research was needed. 
																	Customization operating transom historically operable transom windows above doors played a role in the heating and cooling in a home. 
															
													
									
	
		
	
																	Transom or transom window is also the customary u s. 
																	We do offer transom windows by special order through the home depot stores. 
																	Operable transoms have sashes that can be opened or closed to help regulate the temperature in a room when the door is closed. 
																	This contrasts with a mullion a vertical structural member.