This 50,000 square-foot building has seen continuous use for more than 100 years: first as the Gleason-Tiebout glass factory, then as Manhattan Door factory. It is named for the Knock-Down door frame that was invented here in 1956 by Samuel Sklar and remains an industry standard to this day. The frame could be shipped in pieces — or “knocked down” — and installed into existing walls, revolutionizing the speed and efficiency of building construction. The factory has since remained in the Sklar family and is again a site for innovation. Having undergone a renovation that is equal parts preservationist and state of the art, Knockdown Center now produces and hosts concerts, performances, nightlife and exhibitions that respond to its unique architecture and dimensions.