Home Purchase Mortgage Calculators
Mortgage Program Calculators
As long as the property owner holds legal title, the owner can transfer 100% or a fractional interest in the property without consent of a third party. Most mortgages, however, have an alienation clause that allows the lender to foreclose on the mortgage in the event that 100% ownership of a property is transferred without lender approval. As long as the full 100% ownership interest in the property is not transferred and the existing owner remains on the title in some form of fractional interest, then the alienation clause should not be triggered and the lender will continue to accept payment from the existing owner
To answer your second question, it is possible for someone to own a percentage interest in a property and that ownership percentage will be stated in the grant deed.
This is a legal matter and must be handled appropriately. A qualified real estate attorney should be able to guide you through these matters.