Texas Health and Safety Code - HEALTH & SAFETY § 766.002. Smoke Detector Requirement

(a) Each one-family or two-family dwelling constructed in this state must have working smoke detectors installed in the dwelling in accordance with the smoke detector requirements of the building code in effect in the political subdivision in which the dwelling is located, including performance, location, and power source requirements.

(b) If a one-family or two-family dwelling does not comply with the smoke detector requirements of the building code in effect in the political subdivision in which the dwelling is located, any home improvement to the dwelling that requires the issuance of a building permit must include the installation of smoke detectors in accordance with the building code in effect in the political subdivision in which the dwelling is located, including performance, location, and power source requirements.