At 51-years-old, the Inland Steel Building seems young for a historic structure. (Why do we feel like we're hitting on a building?) But it's getting a facelift from MacRostie Historic Advisors, and we tagged along yesterday as MacRostie's Allen Johnson used NeoCon as an excuse to take architecture buffs on a tour.

Why now for one of the first modern skyscrapers? Allen says new historic tax credits are available to  improve the Skidmore Owings  and  Merrill designed building. The catch? It has to keep the majority of exterior materials the same.

The building's unusually small floorplates are a challenge for its owners, who include legendary Chicago architect Frank Gehry. While several floors are vacant, this one has some of the original panels in place (the window-topped offices at the back middle). Another challenge: the window caulkings, which melt at 82 degrees, making a mess for managers. (We suggested just using Celsius and were kindly escorted out.) MacRostie is trying to find a way to replace some of the glass. Around town, the firm is also working on the Sears Complex  and the old Spiegel building, which will become affordable housing.