(a) The authority of the occupying co-owner to act as an agent and attorney-in-fact is limited to the authority to enter into a contract giving rise to a mechanic’s and materialman’s lien and to execute a deed of trust for the purpose of preserving or improving the residential property. The occupying co-owner is the sole obligor of the debt incurred under the contract and secured by the deed of trust.
(b) A lien that arises under a contract entered into by an occupying co-owner under this section is not subject to repudiation or disaffirmance by another co-owner.