41 C.F.R. § 105-8.150-2
(b) Historic preservation programs. In meeting the requirements of § 105-8.105-1 in historic preservation programs, the agency shall give priority to methods that provide physical access to individuals with handicaps. In cases where a physical alteration to a historic property is not required because of § 105-8.105-1(b) or § 105-8.154 alternative methods of achieving program accessibility include—