Legal Question in Real Estate Law in California

It depends on what type of law you are talking about. The statutes and codes are generally created at the state level. Some federal laws could apply also. Zoning, building and other ordinances would generally be set at the county or city level.

All three do!

The answers you have received are correct, but let me clarify and explain further. Our multi-tiered system of government results in laws being made about real estate as well as many other things at each level of government, as the others have pointed out. The other issue, though, is which level controls what. This is what lawyers call "preemption." State law preempts city and county law to the extent there is a state law on the topic AND the state law is intended to be controlling no matter what a city or county does. So, for example, a city or county cannot pass their own real estate broker licensing rules and they cannot require more than the state requires in order to be a qualified real estate broker. By comparison, cities are free to pass eviction control laws to go with rent control laws, since the state has no laws on the subject. BUT the Ellis Act puts some limits on what those eviction control laws say, including that they must allow landlords to evict people to remove the rental property from the market entirely. As between cities and counties things are a little different. Generally county laws exist to govern only in the absence of city laws. So for the most part they only apply in areas of a county that are outside the city limits of any city. With rare exceptions cities' laws control within city limits. But not always. My favorite example of how complicated this can become is the subject of fireworks. State law says certain fireworks are totally illegal no matter what, but other "safe and sane" fireworks may be sold and used in California IF the county passe a law allowing them in that particular county. Some counties prohibit them entirely. Some counties permit them, but individual cities may ban them. Other counties ban them but allow cities to override that within the city limits. Alameda and the city of Dublin are an example there. Fireworks are prohibited in Alameda County, unless you are in a city that allows them. Dublin allows them. Were this all comes into play in real estate most often is zoning, planning and building codes. In that area of real estate law, you will find a situation much like the fireworks. Some things are state controlled. Some are county controlled. Some are county controlled unless a city supersedes the county. And some things are not subject to any laws unless a city decides to pass a law on it.