Photo: Julian Wass

Make more floor. By extending the existing upstairs storage area, the couple turned 887 square feet into more like 1,200 square feet of usable space. Having a second level for sleeping and working conveys a sense of "a big family home," says Cernuschi.

Forgo walls. Open metal railings on all loft edges prevent the upper-floor spaces from feeling confined.

Do a disappearing act. Clunky speakers have no place here. During loft construction, an electrician installed white JBL built-ins flush against the ceiling. "The sound system is so good, you can watch a movie from the whole house," Cernuschi says.