Q: What are the financial implications of selling my home, building an ADU on my son & daughter in law's property?

A: I think what you are really asking about are the legal implications. As a lawyer my concern would be how you protect your investment in the new ADU unless you have some type of ownership in the real estate that it is sitting on. This would make the situation very complicated because you are probably building on a property that could not be subdivided into more than one parcel due to the zoning restrictions. Putting your name on the property with your son and daughter-in-law could be very compromising in terms of figuring out how to keep your interest separate without causing problems to the remaining owners period for example, as you age, you may need to liquidate your Holdings in order to get Medicaid to pay for long-term care should you require assisted living or a nursing home period I realize you may think that your son and daughter-in-law are going to care for you comma but certain conditions are impossible to take care of it home. So if this situation came up Medicaid will refuse to pay for your care until you liquidate all your property and use that money on your care. This may mean that your son and daughter-in-law will have to pay you for the value of the dwelling and this may come at a time when they don't have sufficient cash to buy you out. Other problems could come up like somebody has financial trouble and a creditor comes after the real estate to pay a judgement. What if your son and daughter-in-law don't pay the property taxes and the property get seeds in a tax lien foreclosure. There are other things that can happen. I just don't think it is wise to have a real estate investment that can't be separately owned by you. That doesn't mean that the situation is impossible. It just means that you will want to go and talk to an attorney and figure out if there is a good way to structure this that will protect everybody. You will also want to check for zoning restrictions and construction code requirements in the location where you plan to build. There is no sense working out the financial arrangements if building the structure is not allowed. So check on that first.