Research and experience show that heating costs can be substantially reduced, especially in colder climates, by insulating concrete walls. There are a number of insulation systems and materials which are readily available and easy to install. Three basic types of thermal insulation are available rigid board, batt or blanket, and spray-on. Concrete walls can be insulated on the interior or exterior face, or by embedding the material within the wall.
Interior installation, using the rigid board, batt, or spray-on methods, is the least expensive method. Because it isolates the concrete's thermal mass from the inside space, however, it is the least desirable from the standpoint of energy conservation. Exterior insulation, usually rigid board covered by a finished surface such as plaster or stucco, is generally the most expensive method of insulation; but the extra energy savings often offset the higher cost. Rigid board exterior insulation systems need little or no maintenance, and varied exterior surface finishes are available to blend with any kind of architecture.
Embedded rigid board insulation in wall panels is increasingly popular for precast and tilt-up walls. The insulation becomes an integral part of the wall panel when the concrete is placed. For precast and site cast walls, this method of insulation provides many advantages such as effective thermal mass and protection of the insulation from the environment.