After living in what was once a poky little Venice, California, bungalow for nearly 20 years, married architects Frank Clementi and Julie Smith-Clementi of the Los Angeles-firm Rios Clementi Hale Studios have just finished an arresting addition. A top-floor master bedroom is encased in nearly three dozen beams, the yard has gotten an overhaul, and the pair could not be happier. Frank gives us the tour.