A Guest House - Is it Legal? Yes and no. There are several Los Angeles none Luxury Neighborhoods that have legal guest houses that were built prior to 1950. These homes were built as an accessory to a Single Family Dwelling on the same lot. They have sleeping rooms, full bathrooms, but NO Kitchens. Somewhat similar to an original hotel or motel - No Kitchen. Also they're not designed for long term occupancy. So using it as a rental property may be illegal, but using it as a Guest House as defined in the City of Los Angeles Zoning Manual and Commentary section 12.03 page 21 is legal.
However, it is quite common in Los Angeles for homeowners to construct a separate dwelling. The workmanship may be professional, but is it legal. Their listing agent may refer to it as a guest house, guest quarters or mother-in-law quarters. But the name does not make it legal. The key word in the definition of a Guest House is No Kitchen.
Before completing the purchase of such a property, you may want to make sure you have a legal Guest House. This could be accomplished by stopping by the city of Los Angeles Department of Building and Safety. There you could verify the permits and save yourself time, money and frustration in the future.
So if you happen to have the opportunity to purchase one of these legal hidden gems, enjoy it. It's like the hard wood floors under the carpet - included in the sale, but not in the price.