HB 369 amends the Texas Local Government Code to prohibit municipalities from adopting or enforcing ordinances or zoning changes that would allow more than one single-family dwelling on residential lots zoned for single-family use as of September 1, 2023. Municipalities may only enact such regulations if they notify affected property owners within 200 feet and obtain their consent through affidavits. The bill also provides standing for injured parties or their representatives to bring actions against municipalities violating this restriction. The bill takes effect immediately with a supermajority vote or on September 1, 2025.