Which of the following properties would require a lead disclosure?

A lead disclosure is required for properties built before 1978 because that is when the federal government banned the use of lead-based paint in residential properties. This regulation ensures that potential buyers or renters are informed about the presence of lead hazards, particularly in homes that may have been constructed using such materials.

In this case, the duplex built in 1959 falls within the timeframe where lead-based paint was likely used. As a result, it is subject to the lead disclosure requirement to protect occupants, especially children, from the risks associated with lead exposure, which can have serious health consequences.

Properties such as the commercial building built in 1960 may have different regulations concerning lead disclosures, particularly if they are not primarily residential. Similarly, the duplex built in 1979 and the single-family home built in 1999 are also outside the requirement, as they were constructed after lead-based paint was banned for residential use. Therefore, these properties do not necessitate a lead disclosure.