Code Requirements
Texas recently updated its energy code requirements for both residential and commercial construction. Beginning April 1, 2011, the 2009 International Energy Conservation Code (IECC) will go into effect for all construction other than single-family homes. And on January 1, 2012, the 2009 International Residential Code will go into effect for single-family homes. The 2012 IECC requirements are presented in the table below or click here for a one-page guide to window requirements under the 2009 IECC.
Jurisdictions that wish to accomplish additional energy savings may also consider adopting the requirements of the 2012 IECC. The 2012 IECC incorporates an additional 15% energy savings through improvements in windows, insulation, air sealing, and other measures. For jurisdictions looking to amend a handful of the energy-saving measures (without adopting the entire 2012 IECC), a short list of three amendments called the “Texas Model Amendment” can be adopted. Click here for a white paper on the Texas Model Amendment.
Different Climate Zones/Packages for Texas IECC Code Compliance
IECC 2009 and 2012 Solar Heat Gain Coefficient (SHGC) and U-factor Requirements in Texas
Solar Heat Gain Coefficient (SHGC)
Texas will soon require a maximum 0.30 solar heat gain coefficient (SHGC) for windows, glazed doors and skylights in all construction other than single-family homes. Single family homes complying with the prescriptive option of the IRC may meet a 0.35 SHGC, but in the 2012 editions of these codes, both IECC and IRC require a 0.25 SHGC in climate zones 2-3 and a 0.40 SHGC in climate zone 4. This is true of both new construction and remodeling projects. Builders can incorporate future energy requirements in today’s buildings, providing a good head start on saving homeowners money in energy bills.
U-factor
U-factor requirements also improved significantly in climate zones 2-4 in the 2009 and 2012 IECC. While low U-factor windows are important in all climate zones, low U-factors are particularly important where buildings are heated more often (as in climate zones 3-4). As with SHGC, jurisdictions that wish to incorporate additional energy efficiency can look either to the 2012 IECC or to the Texas Model Amendment for the improved values.
Air Leakage
The code requires that windows be labeled to show that they meet the IECC's air infiltration requirements of less than or equal to 0.30 cfm per square foot of window area.
For Background information on Texas energy codes or a Step-byStep Guide on meeting code requirements in Texas, visit the following:
