As of January 2012, new single family residential construction in Texas must meet International Residential Code (IRC) energy efficiency provisions. Owners of existing structures don't have to change their homes' insulation, but they could nonetheless save a lot of money and energy by retrofitting their homes to meet these regulations. Learning the insulation requirements for homes in Texas can help you make smart decisions about your home's heating and cooling efficiency.
Attics and Ceilings
Uninsulated attic spaces are responsible for significant heat loss, since heat rises in a building. Residents of southern and central Texas should insulate their attics to at least R-30, or about 9.5 inches of conventional fiberglass batt insulation. If you live in the Texas Panhandle, consider increasing your insulation level to at least R-38.
Insulating basement walls can make finished basement spaces more comfortable and keep heat from leaching into the surrounding earth. The IRC and current Texas code require continuous basement insulation to at least R-10 or cavity insulation to a value of R-15. Basement spaces can be damp and prone to mold, so many homeowners prefer to install rigid foam insulation instead of fiberglass batting, which mildew when wet.
Floors and Walls
Insulation in floors and walls keeps heat inside a room and can allow homeowners to spend less energy heating unused spaces. Insulate wall cavities in Texas homes to R-13 to R-15. In southern Texas, insulate walls in gas- or oil-heated homes to R-13, and walls in homes with electric heat to a minimum of R-19. In central and northern Texas, insulate all floors to at least R-25.
The IRC allows for less insulation in many areas than the stricter International Energy Conservation Code. Insulating homes to IECC standards provides more protection against heat loss and greater energy savings but is not required by Texas law in either new or existing construction. According to the North American Insulation Manufacturers Association, the IECC is the model building code for the United States, however. If you choose to retrofit your home's insulation, consider installing new material to this stricter standard for greater savings.