underlayment
A layer of wood between the sub-floor and the floor. 

underwriters' knot
A code-approved knot tied at the end of an electrical cord to prevent the wires from being pulled away from their connection to electrical terminals. 

Underwriting
In mortgage lending, the process of determining the risks involved in a particular loan and establishing suitable terms and conditions for the loan.

underwriting fee
A fee charged by the lender to verify information on the loan application, authenticate the property's worth as collateral, and make a final determination about whether to grant a loan to the applicant. 

undisclosed heir
A person who claims the right to a piece of property after the death of an owner without a will.

undisclosed spouse
A marital partner who can claim the right to a piece of property but is not identified in the owner's will. 

unilateral contract
A one-sided contract. If one party makes a promise to do something, the second party is not legally required to perform. If the second party does comply, however, the first party is obligated to keep its promise. 

unrecorded deed
A deed that transfers ownership from one party to another without being officially recorded. 

unsecured loan
Any loan that is not backed by collateral. 

upgrades
Options offered to buyers in a new-home project that go beyond the standard carpeting, lighting, finish carpentry, and other amenities. 

upzoning
The process in which a property is zoned from a lower to a higher use. 

urban sprawl
The unplanned expansion of development over a large area. 

U.S. Department of Housing and Urban Development
Also known as HUD. A federal agency that oversees the Federal Housing Administration and a variety of housing and community development programs. 

Usury
Interest charged in excess of the legal rate established by law.