Under the ADA, what are the access obligations of an historic home, now operating as a museum open to the public?

Alterations to historic properties must comply with the specific provisions governing historic properties in the Americans with Disabilities Act Architectural Guidelines or the Uniform Federal Accessibility Standards, to the maximum extent feasible.

Under those provisions, alterations should be done in full compliance with the alterations standards for other types of buildings. However, if following the usual standards would threaten or destroy the historic significance of a feature of the bui...