Relating to municipal and county regulation of accessory dwelling units; authorizing a fee.

SB 673 prevents Texas cities and counties from banning or restricting accessory dwelling units (ADUs) - secondary housing units on single-family lots - from being built, leased, or converted. It blocks local rules requiring parking for small lots, minimum lot sizes, or most fees (like impact fees), but allows standard building code requirements and height/setback limits. Local governments can still set design rules for ADUs, such as maximum size or setbacks, and may charge fees only if the unit requires new infrastructure like water connections. This bill directly affects homeowners seeking to add ADUs and local governments managing zoning regulations.