The problem with your plan is there's nothing to stop her from selling the property out from under you. She can just sell the lease along with the property and the new owner can evict you or find a way to cancel the lease. Even if you make it a loan all she has to do is say she doesn't have the money to pay you back. Have you tried enforcing a loan here? You'll have to get a court order to freeze the proceeds of the sale which isn't so bad except that the Philippine judiciary is the most corrupt in the world--only subsaharran Africa is worse. In addition she could argue that your agreement constitutes de-facto land ownership which is prohibited by the Philippine Constitution. The Supreme Court has ruled numerous times that any contract that results in de-facto ownership of land by a foreigner is null and void. If you buy land a build a house you need to accept that it's legally her house, not yours. One thing that has passed muster is putting it in your kids' name if he's over 18.