INTRODUCTION

Doors, windows and ventilators are important and main fixtures in a building which play vital role in the comfortable usage of a building.

Door is a framework with shutters made of wood, steel, aluminium or a combination of these materials (with glass wherever needed), which is secured in an opening left in the wall for the purposes of providing access to the users of the structure. For small openings, door is provided with one leaf or shutter and for larger openings two or more shutters may be provided.

Window is a framework with shutters fixed in an opening left in the wall for the purpose of providing daylight, vision and ventilation. The window shutters may be of wood or glass. All materials used for construction of door may be used for window also.

Ventilator is a window having small heights with shutters pivoted and fixed at the top of the door or window.