What Are Squatters' Legal Rights?
    In San Francisco, there are no real "squatters' rights," such as a right to occupancy after 30 days of squatting. Some cities do have laws which say that if a squatter simply squats for 30 days, she then has acquired rights to the housing and is no longer a trespasser.
    There are local and state laws here which provide a person with tenants rights after thirty days, but these are applicable only to traditional rental situations. They do not cover squatting (except indirectly, as will be described), and some people familiar with the thirty day residency requirement for tenants' rights in residential hotels mistakenly think this is applicable to squatting as well. Some other cities do have true squatters' rights which take into account the facts that the squatter is not paying rent and may not have the permission of the landlord.
    In San Francisco, the first step to acquiring some sort of squatters' rights is to try to obtain tenants' rights. Until some level of tenants' rights are acquired, the squatter is technically a trespasser.

Getting Tenants' Rights For Squatters
    Getting tenants' rights as a squatter is difficult but it's not impossible, and early on what's most important is at least acquiring the appearance of tenants' rights, since the most basic aspect of a tenant is that she is someone the police won't arrest as a trespasser.
    There are two basic problems squatters have in gaining tenants' rights:
•They are not paying any rent.
•They are living there without the landlord's permission.
But as impossible as it seems to get past these hurdles, it is do-able.
First, rent does not necessarily have to be cash. Sure, that's the most common, but rent is also frequently paid through labor (resident managers, caretakers, etc.). What makes a rental contract is "consideration:" that is, you are getting housing in exchange for something (usually money), but in the case of squatting, squatters need to realize that they are getting the housing in exchange for watching over it, making repairs, cleaning it up, etc.
    Second, the landlord's permission does not necessarily have to be explicit permission or written down. A rental agreement can be written, oral or implied by the conduct of the landlord.
Thus many squatters have found themselves in a squat which the landlord has known about and has given up (for whatever reason) trying to get rid of them. Squatters can make an argument that, when discovered by the landlord, they made an oral agreement with him to live there in exchange for maintenance and security of the property. (One Homes Not Jails squat was successful in establishing such tenants' rights and even successfully fought the landlord's attempt to demolish the housing to build condos.)
    But probably the most important step and the first step which should be taken is to create the appearance of tenants' rights. This is pretty easy and can forestall actions to evict you as a trespasser, giving you time to establish more solid rights (as described above).
Creating the appearance of a tenancy is based first on the fact that police are not supposed to arrest you as a trespasser unless they are acting on the complaint of the property owner. More importantly, police training in a trespassing situation instructs them to first determine if the person may be a tenant. Police are instructed to ask for rent receipts, utility bills or mail at the address. Police Training Bulletin 84-05 says: "If any material showing a right to possession is produced, however arguable it may be, the burden shifts to the property owner or agent to prove the elements required for a trespass violation . . . members should not presume a person to be a trespasser." (See Appendix for this Training Bulletin.) If the burden is shifted back to the owner, that means the police will tell him it's a "civil matter" and must be addressed in court (i.e., through a formal eviction).
When squatting, people should anticipate that there will be some type of encounter with the police at some point and should immediately begin preparing for this.
    The first thing to do is to make it look more of a home than a squat. Getting some furniture and possessions inside helps a lot. If the police come by and see that you're cooking dinner, reading or watching television they're much more likely to buy an argument that you have permission to be there and are really tenants. If it obviously looks like a squat you're just crashing in for the night, they're likely to ignore their training and procedures and will be happy to haul you off to the station "and let god and a judge sort it out later" (as one officer told squatters).
The second thing to do is to get some utilities legally in your name and get some mail sent to your squat. At first, squatters often do whatever is necessary to get the electricity and water working, but once you have an idea the squat might be a solid one, it's a good idea to get them turned on legally in your name. This is relatively easy, since most utility companies don't assume you're squatting and won't ask for any proof of tenancy. You should also have some mail sent to you and arrange for services like telephones and cable TV if you can afford them. Doing all this will give you a fistful of paper to show the police and raise serious doubts in their mind as to whether or not you're actually a trespasser.
    If you have a place looking like your home and have some mail and utility bills, you're likely to be successful in a face off with the police, even if the owner is there as well. For such a face off, it's also a good idea to have all your legal arguments down: "Mr. Smith has been letting us live here to keep an eye on the place and fix it up, but seems to have changed his mind 'cause he found someone else who'll pay him money to be his caretakers."
In most cases, though, the first complaint will actually come from a neighbor who's suspicious. In such a case, having documentation is doubly valuable. But also gently remind the police that they need some type of complaint from the owner to evict you as a trespasser. You might even call their bluff and provide the police the name of the owner and ask them to call him.

Long-term Rights: Adverse Possession
    Squatting can actually lead to the total legal possession of the housing, through what's called "adverse possession."
    Sometimes, squatters get lucky and find a squat which the landlord seems to have really abandoned. Police and neighbors have been dealt with successfully and after many months the landlord still hasn't complained or been seen. In that case, squatters might start laying plans for gaining adverse possession.
    California Code of Civil Procedure   321 and 325 deal with the most relevant factors of adverse possession. Generally, the law says that a claim to adverse possession can be made after five years of possession and after the adverse possessors have paid the taxes on the property.
Adverse possession has been interpreted to mean "open and notorious" possession, in the sense that the squatting has been done on a level where the squatters' presence is not hidden and the landlord could have reasonably gained knowledge of the possession. (In other words, squatters who arrive at midnight and clear out by 5 a.m. every day for five years might not meet the requirements of "open and notorious.")
    Code of Civil Procedure  321 requires the property to have been "held and possessed adversely to such legal title for five years." Section 325 sets the requirement for the payment of taxes and also includes a provision that the property be "cultivated or improved" (which can be repairs, painting, etc.).
    When a squatter gets into the position where adverse possession becomes a possibility, the greatest hurdle is often the payment of taxes, mainly because the landlord can pay the taxes on the 364th day of the 5th year and defeat the squatter's claim to adverse possession (which is exactly what happened at a San Francisco squat in the 1970s). If squatters begin getting a substantial length of possession under their belt, it's imperative that they begin saving up to pay the taxes in order to finalize their claim.