Though hard to spot, another gap separates the new attic catwalk—which runs between the guest and master bedrooms—from the old walls. As with the living room ceiling, says Shively, "I wanted the new parts to float and have a sense of movement in the space." A steel structure underneath the walkway does, however, connect to the walls. The white oak floors also help the new attic level blend with the rest of the house.  Photo 7 of 8 in A Chicago Renovation Taps Into its Attic to Almost Double its Square Footage