At first I was going to do a big boom and build a new house from scratch,” says architect Gerardo Cerda about his initial plans for the Bucktown home he shares with his wife, Lauren, and their three young daughters. “Then at the last minute I reverted to Plan B.” Not that Gerardo, a principal in the firm Froelich Kim + Cerda Architecture, was compromising his vision. “Plan A—tearing it down—just never felt right,” he says. “I became more and more interested in the idea of taking a simple brick building and re-energizing it.”

It’s hard to believe this joyful, airy place was ever a claustrophobic two-flat honeycombed with windowless halls and tight little rooms. “It was a very humble building with no character,” notes 41-year-old Gerardo, who preserved the original façade (the structure dates to about 1908) as a neighborhood-compatible entrée into a spectacular new 3,500-square-foot single-family home. Hundred-year-old exposed brick walls in the front rooms transition to a 21st-century kitchen/family room addition at the rear. And a wall of glass allows sunlight to flood the room while making a verdant little green­sward and enormous oak tree out back very much part of the living space. “In the summer the doors are always open,” says Lauren. “It’s such a healthy way to live.”

Gerardo’s boldest move was the design of the upstairs terrace off the master bedroom, where an open-air rectangle of stucco frames what is essentially an outdoor room. It’s a strong sculptural statement. “If you look out the window you see all these random wooden decks. Ours looks so different, almost tropical,” says Lauren. “I wanted another way to make the house uniquely mine,” says Gerardo of the personal stamp the terrace puts on the place.

The kitchen bears a different stamp—an Italian one. Gerardo designed it with the help of Roman-born Chicagoan Luca Lanzetta, owner of the kitchen showroom Ernestomeda. Gerardo says he becomes more enamored each day with the beauty of the Italian cabinets’ cozy minimalism. “I love the warmth of the rift-cut oak and the clean lines,” he says. “This kitchen keeps things so open, flowing indoors to outdoors, we feel like we have a lot of space. And that feels so good.” Not bad for a Plan B.