This request concerns the requirements of Section 9.2.1.1 of ASHRAE 90.1-1999 which states that buildings over 5000sf must include automatic lighting shutoff for interior spaces. It gives three strategies for accomplishing the requirement: a time-clock, occupancy sensors, or occupant intervention. The Children\'s Museum of Pittsburgh design incorporates occupancy sensors into all corridor spaces, vestibules, toilet rooms, museum office spaces, tenant office spaces and general offices. The remaining areas are program spaces. They have been designed with single-pole toggle switches to control the luminaires within that space by occupant intervention. Some of the areas have multiple circuits, but all are controlled with a single master switch. This control strategy is based on the following: 1. The Museum\'s Security and Management Plan requires the program spaces to be lit while the facility is open to the public for two reasons. First, the program spaces are designed to be visible and inviting from a distance, thus welcoming people to enter and explore. If visitors see a dark room, they are unlikely to approach an area, thus creating an insecure and unsettling experience. Second, the best way for the Museum to be confident that no visitors or staff are still in the program spaces at the end of the day is to perform a final walkthrough. At closing, the staff is required to inspect each program space and turn off the lights once an area has been cleared. As the Exhibit Staff reviews and then leaves an area, the lights are turned off and they move to the next area. The staff fans out to the different areas, and lights off means that an area has been cleared. The Manager on Duty is responsible to confirm that all the procedures have been followed. Occupancy sensors could compromise both the engaging nature of the exhibits and the security of the museum while manual controls fulfill an important security function. 2. Often, the museum is rented for evening and off hour events. The Museum has two people who will have access to the facility management control systems. With this limited Facility Staff, timers would create management strategies requiring multiple people access to the museum\'s facility controls. The Facility Staff focus on providing a clean, safe and secure facility for the visitor. Timers would add a layer of management complexity that would have to be adjusted with each event, thus opening up the museum to security challenges and leaving the facility vulnerable. When the facility is rented, the Guest Services staff working the event is required to perform a final walk through just as they would at the end of a typical day. The final walkthrough enables the Staff to inventory the various exhibits for safe operation, needed materials and facility reports. With this approach including daily updates on the status of the exhibits, the Museum ensures that no one is in the building, the facility is safe, exhibit components are shut down and the room lights are turned off. In summary, occupancy sensors have been used where appropriate and consistent with the function of the facility. For the remaining spaces neither a time-clock nor occupancy sensors are appropriate, leaving only occupant intervention. We feel that the occupant intervention protocol that has been established fulfills the objective of minimizing energy use associated with lighting and does so within the overriding need for safety and security in a facility that is open to the public. Will this strategy meet the requirements of the prerequisite?