The last time Blake Trabulsi and Allison Orr had a party at their house in Austin, Texas, it lasted until 5 a.m. Observes Trabulsi: "People are so comfortable here, they never want to leave." That could have something to do with the gentle mien and modest scale of the couple’s ten rooms—–half in a 1930s bungalow and half in a new addition by Rick Black Architect (the Austin partnership of husband-and-wife architects Rick and Cindy Black). As Trabulsi, a graphic designer, and Orr, a choreographer, explain it, they aimed to expand without making the original obsolete. Here’s their story.