10 C.F.R. § 1040.74
(a) Methods to accomplish accessibility. Recipients shall operate each program or activity involving historic properties so that when each part is viewed in its entirety it is readily accessible to and usable by handicapped persons. The recipient shall exhaust subsection (b)(1) (methods to accomplish accessibility without building alterations or structural changes) before proceeding to subsection (b)(2) (methods to accomplish program accessibility resulting in building alterations). The recipient shall exhaust subsection (b)(2) (methods to accomplish accessibility resulting in building alterations) before proceeding to subsection (b)(3) (methods to accomplish accessibility resulting in structural changes).
(1) Methods to accomplish accessibility without building alterations or structural changes. The recipient shall investigate compliance methods which do not alter the historic character or architectural integrity of the property and shall utilize such methods unless such methods are ineffective in achieving accessibility. Such methods may include, but are not limited to:
(b) Modification or waiver of accessibility standards. The applicability of the accessibility standards set forth in these regulations may be modified or waived on a case-by-case basis, upon application to the Director, FAPD, where the recipient can demonstrate that, because of the nature of the activity, the provision of access would be infeasible or would substantially impair the historic, architectural or cultural integrity of the historic property.
(National Historic Preservation Act of 1966, Pub. L. 89-665, 80 Stat 915, 16 U.S.C. 470; 11593, 3 CFR 1971 Comp., p. 154; 36 CFR part 800)
[45 FR 40515, June 13, 1980, as amended at 68 FR 51347, Aug. 26, 2003]