This is information about California's new accessory dwelling unit law. This law, allows owners of single-family or multiple family residences to add legal rentals to their existing buildings. The law is mandatory in all cities and a link to an explanation follows!.
http://www.hcd.ca.gov/policy-research/AccessoryDwellingUnits.shtml
The law allows one to add a legal rental unit to their existing property, by converting a space in their home, or an outbuilding, to an accessory or jr. dwelling unit. A junior accessory dwelling unit would be, 150 ft.² to 500 ft.² & would only require outside access from that room. An accessory dwelling unit, would be 50% of the main structure, up to the maximum of 1200 sq ft.
Only ministerial approval is required for these units. No additional parking would be required, if the accessory dwelling unit, is within one half mile of public transportation. Junior accessory dwelling units require no additional parking at any distance from public transportation. For existing structures, no new sewer, electrical, gas meters or lines, need to be created.
The dilemma, I see, is, with someone adding an additional unit with no parking, then having to deal with the renters, parking the spaces that you normally use. Since, cities will be able to mandate that these units or main structures, need to be owner occupied, I do see potential problems for future sales of these properties. Cities may create covenants, that could be recorded and could transfer with the property. If these covenants, did not allow for future sales to absentee owners or second home buyers, the sales might be limited to only, owner occupied buyers.
The law allows, for carriage houses or granny flats, that currently exist, to be converted to dwelling units. When cities have barriers to the legal use of granny flats or carriage houses as rentals, this law may supersede those restrictions.
This law, was comrised of three bills and other cleanup bills, and may be modified in the future, as City/Consumer concerns become known. Please take the time, to review the information in the link above and call officials in your city to determine what requirements, changes or restrictions might apply.