Legal Question in Real Estate Law in California

If he is on title he owns half the house indefinitely. In fact he could die and his heirs would own his share. And anyone who co-owns a house can force a sale. That does not, however, mean they automatically get 50% of the proceeds, and it is subject to the right of the other co-owner to buy them out instead of selling.

When any co-owner of property wants their money out, they can file what is called a partition action to force a sale of the property and distribution of the proceeds by the court. This results in the property being set for sheriff's sale by the court, like a foreclosure, followed by more court proceedings over the proper distribution. As you can imagine, all this does is get a lower price for the property than if it was marketed and sold, and runs up a lot of attorneys' fees.

So what usually happens instead is the co-owners agree on one of them buying out the other, or a cooperative sale with an agreed broker for market value, and then either a negotiated or court ordered distribution of the proceeds.

If the parties cannot agree on a buy-out or distribution, then the court will decide. It is not automatically 50/50 if one of the co-owners has paid more for the property than the other, either at the outset or over the course of ownership. The rules for what contributions count and which don't (for example one owner paying entirely for a new addition counts, paying for someone to mow the lawn each week doesn't) and what other balancing charges may be applied is a fairly complicated area of the law. So you are going to have to consult an attorney to go over the exact details of what you have spent, etc., to get an idea of what his share would be. You may also want to consider initiating, or at least threatening the partition action yourself to induce him to take a reasonable buy-out. A good attorney can help you with that strategy.

Ultimately, though, unless the house was worth nothing more than the debt at the time you split, and you have some evidence of this agreement that he would just walk away (any witnesses to the agreement for example) he does remain a co-owner and is entitled to some portion of the value of the house.