The 2018 International Residential Code (IRC)
Closure Property of Addition for Natural Numbers Addition of any two natural numbers results in a natural number only. We can represent it as a + b = N, where a and b are any two natural numbers, and N is the natural number set. For example, 4+21=25, here all numbers fall under the natural number set.
In Texas, cities like Houston, Austin, and Dallas have adopted versions of the IRC with local amendments. For example, the 2018 International Residential Code is widely used in many Texas municipalities, though the 2021 IRC is being increasingly adopted in certain areas.
Area codes 210 and 726 are telephone area codes in the North American Numbering Plan (NANP) for San Antonio and most of its innermost suburbs in Bexar County in the U.S. state of Texas. The original area code, 210, was created in an area code split from area code 512 in 1992.
Extraterritorial Jurisdiction (ETJ) The ETJ is the unincorporated land within five miles of the City of San Antonio boundaries and includes all unincorporated territory that is not located in another city's municipal boundary or ETJ.
A good place to start is the website for the local building department or zoning board. There you will find a list of the codes that apply to your area and information on how to comply with them.
The San Antonio Building Code 2021 is based on the International Building Code 2021 (IBC 2021) with amendments and additions.