They are primarily protective screens separating the house as a whole from its surroundings and partitioning the interiors into usable areas. They insulate against heat, cold & noise; they reflect or absorb light & sound; and they house the wires, pipes and ducts for electrical appliances, plumbing and heating. Increasingly they are used as a built – in – storage, furnishings and lighting.
In addition, the wall accomodate conduits for type of electrical wiring or plumbing. Electrical outlets are usually mounted in walls.
Economy
Good walls should have economical to erect, long lasting, require minimum maintenance, keep heating and cooling bills low, and takes little space.
All the five characteristics from one wall may not be possible and hence one should decide what is most important for each wall, because even in one house their functions are not identical. When walls are not necessary for actual enclosure they are replaced by various types of dividers to separate areas without sacrificing a feeling of spaciousness. Collapsible walls, glass walls, panels, screens, open shelves & cabinets, grill work are frequently used in place of actual walls. Sliding wall panels and folding walls are used to make rooms more adaptable to a variety of purposes. Storage walls of various types conserve floor space.
Aesthetics
Building walls frequently become workof an art externally and internally, such as when featuring mosaic work or when murals are painted on them; or as design focus when they exhibit textures or painted finishes for effect. In architecture and civil engineering, the term curtain wall refers to the facade of a building which is not load-bearing but functions as decoration, finish, front, face, or history preservation. Exterior walls shape the mass of the house and establish its relationship to its environments.
Environmental Control
The exterior environment that the wall is subjected to includes environmental control loadings such as thermal, moisture. The performance of the wall system depends on its ability to control, regulate and/or moderate these environmental control loadings on each side of the wall to desired levels.