The homes would be in the community's Softball Neighborhood located at 135 Sun City Blvd., officials said.
The move will increase the number of Sun City's residences from 7,500 to 7,575, said Ethan Harwell, Georgetown's senior planner.
Included in the deal is a parkland fee, or a fee imposed on subdivisions for park preservation, of $825 per unit for the additional units, Harwell said.
Council previously approved a rezoning for the additional housing on May 25.
In other news:
Council voted to re-adopt the 2012 juvenile curfew. Curfew hours are 11 p.m. until 6 a.m. on Sunday through Thursday and midnight to 6 a.m. Friday and Saturday. Council is required to review the juvenile curfew ordinance every three years, Police Chief Wayne Nero said.