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 building, alternative standards may be used.
The decision to use alternative standards for that feature must be made in consultation with the appropriate historic advisory board and interested persons should be invited to participate in the decision-making process.
The alternative requirements for historic buildings or facilities provide a minimal level of access. For example —
1) An accessible route is only required from one site access point (such as the parking lot).
2) A ramp may be steeper than is ordinarily permitted.
3) The accessible entrance does not need to be the one used by the general public.
4) Only one accessible toilet is required and it may be unisex.
5) Accessible routes are only required on the level of the accessible entrance.