Because of the present day trend to simplify the exterior appearance of houses by eliminating unnecessary and costly decoration, architectural expression in houses is obtained to a large degree by the relationship of window areas to solid wall areas. The number and placement of windows, and even the type of windows, affect the architectural character of the house.
While windows must first be selected, sized and located to satisfy interior requirements, minor adjustments in size and/or location may be necessary to provide an acceptable appearance on the exterior of the house. Windows should be so used that the house gives an appearance of continuity, rather than one of unrelated glass and wall areas.
Use of large glass areas usually requires some controls for privacy, both in the daytime and at night. Obvious controls include draperies and blinds. Consideration must be given to the size and the placement of these hangings so that they do not cancel the benefits of breeze. The use of louvres or other opaque types of ventilating units which do not have to be draped is one solution to this problem of privacy with ventilation. Placing windows high in the wall is another effective means of obtaining privacy, especially in bedrooms.
Heat Loss and Heat Gain
Window areas are a major source of heat loss in winter and heat gain in summer. This heat loss and heat gain can be reduced:
- through correct placement of the house on the lot in relation to the sun;
- through design of the house as regards the amount of glass area and its location in the walls; and
- through the use of insulating glass.
Heat is lost through glass and through cracks around the sash operating windows. This loss must be taken into consideration in determining the amount of glass to be used and the design of the heating system. Heat loss may limit the amount of glass in the house, but if insulating windows are used instead of single glazed ones, larger glass areas are possible.
The placement of room heating units (radiators, oil heaters, etc.) below windows eliminates cold draughts since the glass and the air around the windows are warmed.
In controlling heat gain, the location of glass areas is more important than the amount of glass. The house should be placed on the lot, and if necessary shaded so that the rays of the sun can be admitted during the winter when solar heat is desirable, but excluded during the hottest months
This house is not as pleasing in appearance as the one below due to the number of unrelated glass and wall areas.
Windows in this house are sized and placed to form a pleasing relationship between glass and solid wall.
Even though the glass area is large, the occupants of the house can have privacy.
Other aspects to consider in window planning: