DORMER WINDOW, is a window placed in a small gable rising out of a sloping roof, often made use of
(From the Château de Josselin, Brittany, end of the 15th century.) for the purpose of enlarging and lighting the attic or garret-rooms of modern houses. It is also popularly known as a storm-window. Dormers do not appear to have been in use before the middle of the 14th century. After that date they were greatly employed, especially in the later domestic Gothic edifices. Those of the Hôtel de Ville at Rouen are amongst the most splendid examples.