Windows

A windows may be defined as an opening ma& in a wall for the purpose of providing day light, vision and ventilation. The construction of window is identical to that of door. Window consists of a window frame and shutters. The frame consists of two vertical members called jambs, one flat, i.e. horizontal member connecting the jambs at top, down as head and another flat member connecting the jambs at their feet, known as sill. The shutter can be fully glazed, panelled and glazed or only panelled type. Windows are normally provided with two shutter leaves. 

The selection of size, shape, location and the number of windows to be provided in a room depends upon the following considerations : 

1. Size of room to be lighted. 
2. Location of the room and its utility. 
3. Architectural treatment to be given to the building. 
4. Direction of wind and its speed. 
5. Climatic factors prevailing at the site such as humidity & temperature variation. 

Based on these considerations the following thumb rules have been framed to determine the area requirements for windows in a room; and, the size and hence, the number of windows can thus be worked out once total area required for window opening is known : 

• The total area of window openings should normally vary from 10 to 20% of the floor area of the room. In hot and arid regions it could be 10 to 15% of the floor area. When the building is to be located in hot and humid regions, the area of window awnings should vary between 15 to 20% 01 the floor area. 
• In case of public buildings like, schools, offices, factories  hospitals etc., the minimum area of windows should be 20% of the floor area.
• For adequate natural light the total area of glass panes in windows should be at least 8% of the floor area.