; or (v) any combination of the methods described in this subparagraph. (2) At least 60 percent of the exposed facade material above 40 feet shall meet the standard described in paragraph (1)(A) or (1)(B). (3) There shall not be any transparent passageways or corners. (4) All glass adjacent to atria or courtyards containing water features, plants, and other materials attractive to birds shall meet the standard described in paragraph (1)(B). (5) Outside lighting shall be appropriately shielded and minimized subject to security and other mission related requirements. (b) Monitoring The Administrator shall take such actions as may be necessary to ensure that actual bird mortality is monitored at each public building. (c) Existing buildings and lighting (1) In general The Administrator, where practicable and consistent with security and other mission related requirements, as determined by the Administrator, shall reduce exterior building and site lighting for each public building. This paragraph shall not apply to buildings in which the Administrator does not have control of the exterior building and site lighting. (2) Use of automatic control technologies In carrying out paragraph (1), the Administrator shall make use of automatic control technologies, including timers, photo-sensors, and infrared and motion detectors. (d) Additional methods In carrying out the requirements of this section, the Administrator may employ any available methods and strategies that are in accordance with existing effective best practices to reduce bird mortality. (e) Exception for significant cost The requirements of this section shall not apply to any acquisition or substantial alteration described in subsection (a) if the Administrator, after consideration of multiple options, determines that the use of the required building materials and design features would result in a significant additional cost for the project. (f) Exempt buildings This section shall not apply to— (1) any building or site listed, or eligible for listing, on the