By January 1, 2002, all municipalities in Texas had to adopt which building code for residential construction?

The correct choice is the International Residential Code (IRC), which became essential for residential construction in Texas as of January 1, 2002. The IRC provides a comprehensive framework for building safety, sanitation, and structural integrity for one- and two-family dwellings, which is critical for ensuring the safety of residential environments.

The adoption of the IRC across Texas municipalities standardizes the construction practices, making them uniform and transparent for builders, contractors, and homeowners. This code covers various aspects, including planning, foundations, framing, energy efficiency, and safety regulations, thus facilitating a cohesive approach to residential building projects.

The other options, while relevant to aspects of code enforcement and construction, do not pertain specifically to residential buildings in the same comprehensive manner as the IRC. The Texas Code Compliance Code and the International Property Maintenance Code are not solely focused on residential construction; rather, they pertain to broader compliance and property maintenance issues. Furthermore, the International Code Council itself is an organization that develops various codes rather than a specific code adopted for Texas residential construction.