Three areas, three sets of rules
Central Area. Every new single-family residence in the Central Area goes through design review. The City's stated aim is homes that complement the distinct residential neighborhoods, keep the scale and massing of the streetscape, and enhance the garden quality of the city. Review happens at staff level as a Track 1 project or before the Design Review Commission as Track 2.
Hillside Area. The City runs no design review process in the Hillside Area. The standards there cover floor area, height, setbacks, parking, walls and hedges, landscaping, accessory structures, allowable landform alteration, and view preservation. On a hillside lot the grading and the view questions often decide the house.
Trousdale Estates. Trousdale has its own single-family regulations, including rules for construction related to level pads. A Trousdale home starts from those standards rather than the Central Area's.