[3] In the early 2000s, it was announced the museum would be expanding from the old Beaux Arts-style post office into the neighboring vacant Art Deco Buhl Planetarium.

A plan was devised by Koning Eizenberg Architecture, Inc. to connect the two historic structures with a modern glass addition over what was a street called Allegheny Square.

[4][5] In its seasonal "Backyard",[6] the museum grounds includes an interactive environment called "Allegheny Waterworks" which incorporates preserved local architectural relics.

[7] A garden on the grounds once displayed sculptures of Guyasuta, Christopher Gist and others, designed by sculptor Charles Keck and rescued from the Manchester Bridge when it was razed in 1970.

The MAKESHOP, Kindness Gallery, Studio, Backyard, Garage, Garden, Theater, Waterplay, and Nursery areas are ongoing interactive exhibits and encourage touch and play.

Visiting artists offer workshops in a host of media, including pottery, Japanese paper cutting, animation and painting.