1) This was sometimes a reference to the room in which there was a fire or chimney but more particularly it meant the right to use such a room.
Into comparatively modern times, most houses would have only one heated room, and in those circumstances a testator might formerly seek to make sure that those he left behind had access to the fire. In the will of Thomas Brook of Huddersfield, in 1638, his heir Joshua was asked to look after his wife and children att his table att Newhouse … with sufficient houseroome and fyreroome and lodging, meat and drinke, sutable to their Callings. In 1653, Richard Armitage had to provide his apprentice with loudginge, apparell, houseroowme, firerowme, washinge of his cloathes, Honley.