While CSCP’s office is modular, it is not prefab — built someplace else and brought to the site — or modular prefab — where a company sells modules and ships them to the site for assembly. Rather, the modules were constructed on-site, Piralla explains. “It worked out really well because we didn’t have to ship anything. All the steel was bought locally, and all the labor was subcontracted from local companies,” he says. “It’s pouring a little money back into the local economy.”
The design and layout of the structure were developed by Phoenix-based ASUL working with Piralla and based on the available modules developed by ASUL. The project was a “both build” option in which ASUL erected the steel frame, walls and roof, and the clients finalized the interior and exterior, including cladding and mechanicals using a local contractor.
ASUL’s business model, according to its website, is to “create a design and construction methodology allowing for the mass customization of homes. The result of these efforts is an adaptable system capable of producing custom modern homes priced at 25 to 50 percent less than the current market.”
In addition to FEMA requirements for raising the structure to comply with flood-plain restrictions, the residential zoning of the property did not allow for in-law suites, “so we couldn’t have a bathroom,” Piralla recounts. “We work with some interns and assistants, but they can just come to the house. That was just a minor inconvenience. Anyway, we didn’t want to spend extra money on plumbing [and a bathroom], which would take space away from the work space. It wasn’t a problem either way.”
One minor consideration, which as it turns out did not affect the addition, was a restriction of percentage of roof space allowed relative to the square footage of the lot. “That dictates the maximum size of any addition or separate building, but the size [of our office] is perfect; we didn’t want anything larger,” Piralla says. This was not a permeability issue as it might have been in a drier climate but “just so people don’t put up huge McMansions. These are neighborhoods from the 1950s, so you have a few mid-century moderns and mostly ranch houses; it’s suburbia with large yards,” he says by way of explaining the restrictions put in place to maintain that ambiance.
The office space “is a pretty straightforward building,” Piralla says. “It’s constructed of tubular or I-beam steel. The benefit of that is there is no shear, so technically all four walls could have been glass,” an option that was not pursued, however.
The steel-based construction is similar to the 1950 method implemented in architect Pierre Koenig’s Case Study House No. 22 (the Stahl House) in Los Angeles and allows for an easy elevation above the ground required by FEMA for the area. (The case study houses were commissioned by Arts & Architecture magazine after World War II in response to a quest for inexpensive and efficient homes for returning veterans.)
“It being a warmer climate, we wanted to use natural light without overheating the space in the summer. We had a neighbor behind us, preventing us from having a window on the north side, which would have been the best light to have. The larger windows face east, so it’s still the cooler light of the day. On the west, we have a very small band of windows just to get some light in and keep some of the heat out. There are no windows on the south faade of the building to eliminate the heat coming from that side,” Piralla says. Solar shades with 5 percent light penetration provide protection during the hotter months. Windows are argon-filled double-pane.
Four concrete footings support the entire 16- by 20-ft. structure and its 8-ft. deck. “We wanted to have a deck; that way you don’t just have a staircase butting against the building, and it also gives you a little space so whenever you start getting frustrated, you can just walk outside, relax and enjoy the day and then go back inside and work. Our dogs love it because they can see the whole neighborhood; they have their watchtower.”
The exterior cladding is Galvalume, a 55 percent aluminum-zinc alloy coated sheet steel. “It’s low maintenance,” Piralla notes. “Basically you hose it down once a season to get some of the pollen and dust off, and it’s really easy to install. You can get sheets the length of the entire building so there are no horizontal seams.” The corrugated steel “maintains the horizontal language between the two buildings,” he adds.