Residential Walk-Through

A Prefab Expansion

Phoenix, Arizona

Caren Roddy, AIA, LEED AP | Mark Roddy, AIA, LEED AP

BY NORA BURBA TRULSSON

PHOTOGRAPHY BY LIAM FREDERICK

Pre-engineered metal buildings were used to expand the living space of a 1928 bungalow and (at far left) to serve as a garage.

In 1999, when Caren Roddy was single and going to graduate school at Arizona State University, she bought a 1928 bungalow in a historic Phoenix neighborhood. The 900-square-foot, two-bedroom house was, at the time, perfect for Caren, a project manager for the Phoenix office of Gilbane Building Company. "I had a five-year plan," says Caren. "I was going to get my graduate degree, establish a career, then move on to a different house."

Fast-forward a few years. Caren met and married architect Mark Roddy, design principal for SmithGroup Phoenix, and that was followed by the birth of their son. The small historic house went from being perfect for a single person to cramped for a family. After mulling over their options, the couple decided an expansion was in order.

"We both love being downtown in this historic neighborhood," says Mark, who is the lead designer for SmithGroup's office/workplace studio, "and we're both interested in the concept of prefab buildings."

The home office in the new addition features recycled shelving.

Doing a bit of research, the two opted for an addition in the form of a pre-engineered metal building from a local company that specializes in industrial, agricultural and warehouse structures. Though the Roddys were going for a contemporary look, they specified a 700-square-foot metal structure that would match the height, scale and roof pitch of the original house.

"Because this is a historic district, we had to go through both design and historic review," explains Caren. "In a historic district, the City of Phoenix doesn't want you to expand the house by matching the existing structure. They want a clear delineation of old and new. They also don't want you to alter the historic streetscape of the neighborhood."

The additions created a series of outdoor rooms in the garden, including dining and pool patios.

In plan, the addition began at the rear of the old house. Mark and Caren opened up the back of the kitchen and designed a conventionally framed dining room to act as a connector between the old house and the new rectangular metal structure. Entering the new space from the dining room, the addition contains a master bedroom and bath on the north side of the building. A walk-through closet behind the bedroom leads to a linear home office and laundry room, sited on the south side of the addition.

The corrugated metal structure was manufactured offsite as a "kit," trucked to the Roddy property and assembled on-site in two days. The raw steel exterior was left untreated and allowed to rust, creating a ruddy, patinaed finish that blends into the landscape and neighborhood. Spray foam applied between the metal frame and the interior drywall provides not only insulation, but a vapor barrier and sound-deadening properties as well.

The exisiting house and the pre-engineered addition were connected by a conventionally built dining room, which opens to garden areas via overscale storefront doors.

Much of the addition's airy grace comes from the use of large expanses of glass, including several 5-by-8-foot pieces of low-E, high-performance glass Caren salvaged from a commercial construction Dumpster. In the dining room, two overscale storefront doors, framed in anodized aluminum, swing out to allow access to the outdoors. A large fixed-glass window on the home's north side casts daylight into the hallway leading from the dining room to the master bedroom. The bedroom itself was designed to resemble an old-fashioned sleeping porch found in the early-1900s, pre–air conditioning houses of Phoenix. Two large custom pocket windows, raised 18 inches off the floor, meet in a corner. The windows can be pulled back and screens pulled into place for natural ventilation. To keep utility costs down, no windows were used on the south side of the metal addition.

Inside, the addition's contemporary motif was underscored with terrazzo flooring. The home office includes a wall full of salvaged shelves, held up by a Unistrut support system. Glass tile adds shimmer to the master bathroom, where sleek European-style fixtures reiterate the clean, open design scheme. The laundry room, also sparked by glass tile, doubles as a mini art gallery, as does an adjacent hallway.

Pocket windows retract and screens snap into place to create an old-fashioned sleeping porch for the new addition's master bedroom.

During the expansion project, Caren and Mark also added a garage to the far back of the property, also a pre-engineered metal building by the same company, designed to be a smaller match for the addition.

The addition and the freestanding garage created some opportunities within the landscape. "Before we did the addition and the garage, the yard was just one big open space," explains Mark. "The new structures actually organized the yard into smaller 'rooms' that work better for the family." The Roddys added a pool and dining/living patio to the south side of the house and created a lawn and garden area that angles between the house, pool and garage. A dog run and mechanical area take up the north side of the property.

Sleek fixtures and glass tile combine in the master bathroom.

The project was completed in 2007, giving the family its much-desired breathing room. It also gave Caren and Mark recognition from their peers, in the form of a 2007 design award from AIA Arizona's Home of the Year competition, being named the 2008 "Best Metal Building" in Metal Architecture's design competition, and winning one of the Phoenix-based Valley Forward Association's 2008 Environmental Excellence Awards.

Architecture: Mark Roddy and Caren Roddy.

General contractor: Caren Roddy.

Pre-engineered addition and garage: Bunger Steel, Inc., 8112 W. Buckeye Rd., Phoenix, AZ 85043; www.bungersteel.com or (623) 936-7181.

Spray foam insulation: Icynene, www.icynene.com.

Custom windows and doors: Arcadia Inc., 3225 E. Washington Blvd., Vernon, CA 90023; (323) 269-7300 or www.arcadiaincorporated.com.

Terrazzo flooring: Advance Terrazzo, 1217 E. Gibson Lane, Phoenix, AZ 85034; (602) 253-6915 or www.advanceterrazzo.com.

Cabinetry: IKEA, www.ikea.com.

Bathtub: Duravit, www.duravit.com.

Unistrut shelving support: Unistrut Metal Framing System, www.unistrut.com.

See Web-only extra images of this project.