The following information is taken from the Code Information section at the Efficient Windows Collaborative:
Many states and local jurisdictions, including Texas, have adopted the 2000 or 2003 IECC© and many more are currently reviewing the IECC for possible adoption. The Responsible Energy Codes Alliance developed the following State Code Guides to assist states and local jurisdictions that have adopted, or are considering adopting, the IECC.
These Guides are compliance aids for determining the IECC requirements for each state and county, but they do NOT include any state-specific or local amendments that have been adopted in the various jurisdictions. The Guides reproduced here are meant to illustrate the IECC requirements for your state or local jurisdiction and are not intended to be an official compliance tool, unless your local code official has approved them as an acceptable method of compliance. Before relying on the values or requirements indicated in these Guides for energy code compliance in your jurisdiction, please contact your local code official. In addition, note that these guides do not address commercial building requirements.