CALIFORNIA FAMILY LAW
...Family Residence/Real Property
......S/P Contributions to S/P Residence
3 Cards On This Topic:

One party’s s/p used to acquire or improve other party’s s/p shall be reimbursed, absent writing to the contrary.

No transmutation occurs when H uses his s/p to improve W's s/p residence.

Money loaned to W after separation to construct house on her s/p lot did not give H a c/p interest therein.