When a couple with an eye for midcentury modern design saw a 1950 home for sale in Mountain Brook, Alabama, they snapped up the residence—never mind that the house was dilapidated and far too small for their growing family of four.

Convinced of the home’s potential, the couple turned to Atlanta–based Surber Barber Choate + Hertlein Architects to resurrect the post-and-beam structure and add a sensitive extension to double the footprint to 3,600 square feet.

Dubbed the Harrison House, the restored and enlarged abode makes a clear distinction between old and new. To respect the original building, the architects placed an open courtyard between the existing single-story structure and the new two-story extension. The extension is connected via an elevated bridge and an open-tread stair that descends through the roof of the original home.