The Historic Review Commission yesterday approved design plans for an expansion of the National Aviary contingent on a landscaping collaboration between the designers and the Allegheny Commons Initiative.

John Francona, chairman of the steering committee of the initiative -- a $16 million restoration of the 84-acre commons, also called West Park -- said his committee is "in full support " provided the footprint does not expand beyond the additional 25,000 square feet. Much of the addition will be vertical, with two new stories over part of the 56-year-old structure.

The project includes a new, open air, rooftop theater for bird-of-prey programs, expanded exhibit and classroom space, and an indoor theater.