HVAC Code Requirements in Texas

Coastal areas subject to long-term erosion and storm-induced shoreline retreat. Construction setbacks and erosion-resistant foundation design may be required.

Wind-Borne Debris Region (WBDR) per 2018 IRC/IBC Section R301.2.1.2: (1) Areas within 1 mile of the coastal mean high water line where the ultimate design wind speed is 130 mph or greater, OR (2) Any area where the ultimate design wind speed is 140 mph or greater. Most of the TDI Designated Catastrophe Area falls within WBDR, but not all inland areas. WBDR designation requires impact protection for fenestration (windows, doors, skylights).

Harris County has PARTIAL TWIA eligibility - NOT the entire county. Eligibility is strictly defined: areas EAST of State Highway 146 AND within city limits of La Porte, Morgan's Point, Pasadena, Seabrook, or Shoreacres. This creates a "hard" eligibility cliff - a structure 50 feet west of Highway 146 may be ineligible for TWIA coverage while its neighbor across the highway is eligible. This is a BINARY determination based on political boundaries, distinct from the physical wind speed gradient.

DOD TIP Zone 1 (Very Heavy) — highest probability of subterranean termite infestation. IRC Section R318.1 requires termite protection measures for all wood structures.

State within or adjacent to the tornado corridor. NOAA SPC data confirms significant tornado frequency. Enhanced structural requirements apply per IRC R301.2.1.2.