Directions from Medical Center: Take South McGregor, turn left on Scott St. and turn right at second light on Holman St. For lot 15G (see below), turn again left on Cullen.
Parking is possible across Cullen Blvd. from SEC (building 529) in either the visitors lot 15G (enter at the kiosk at 513) or at parking meters in 15D (enter from Hohlman --- meters are in the small area on the left).
Map: A large map of the University of Houston Central campus is available here. The figure below shows a detail with the location of the SEC buliding and parking lots 15G and 15D.