A couple of years ago, the team at Lake | Flato Architects got together to brainstorm ideas to help weather the recession. Even with a long list of design awards and a 2004 AIA Firm Award on their resume, the respected San Antonio-based practice was feeling the sting of the slowed-down economy. Associate partner Bill Aylor says the firm had long had a fascination with prefab, and living and working in Texas, where modular sheds and barns were common in the rural locations Lake | Flato often worked, it seemed a natural fit. "During our internal investigations we decided that if we did modular we wanted the designs to accomplish three things," says Aylor. "We wanted to keep costs down, create a design that could have both prefab and site-specific elements combined without compromising design quality, and maintain a sustainable approach."
Location Vanderpool, Texas (Rio Grande watershed)
Gross area 3,000 ft2 (278 m2)
Completed April 2010
Annual purchased energy use* (based on simulation) 26.1 kBtu/ft2 (296.4 MJ/m2), 35% reduction from base case
Annual carbon footprint* (predicted) 8.4 lbs. CO2/ft2 (41.2 kg CO2/m2)
Program Living/kitchen, bath, bedrooms, porch
* Energy and carbon intensity is based on conditioned floor area.
TEAM & SOURCES
Windows Marvin, Integrity
Sloped roofing MBCI, PBC Galvalume
Cabinetwork/custom woodwork Aristocraft
The San Antonio-based firm Lake | Flato joins the prefab party with an adaptable, modernist take on modular housing.
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Aylor is the first to admit that those criteria don't make Lake | Flato's modular effort, called Porch House, particularly unique, but what does single out their effort is the creation of a design process where buildings are created and delivered in keeping with the firm's philosophy and attitude. Known for their responsible, regional, and carefully crafted designs, Lake | Flato offers the Porch House to a broad audience, at a price point for construction and transport of around $150 to $225 per square foot. Aylor and the team researched how other firms have succeeded or failed in their modular efforts, and approached experienced factories across the country to see how agreeable they would be to taking on a partially prefabricated Lake | Flato project. "We got anywhere from 'Yeah' to 'Hell, yeah,' " says Aylor.
With the enthusiasm of several factories behind them, the firm designed a library of options for clients to choose from in order to create a flexible Porch House to fit any site configuration. There are nine different "rooms"—each is 17-feet wide (the limit for transporting), with 10-foot-high ceilings, and floor-to-ceiling windows and doors. These rooms can be used alone; stacked; in a line connected by porches, dogtrots or breezeways; or positioned around an exterior courtyard. The roof is secured onsite, and the porches, decks, terraces, breezeways or dogtrots, carports, and overhangs are then created to take advantage of the unique environmental characteristics of each location. Mechanical systems were carefully chosen to handle the small heating and cooling loads of the units or take on loads distributed between units, and a variety of finishes, cladding, and other options are available, including solar panels, which can reduce energy consumption to net zero. Site work happens in conjunction with the factory construction, and in six to nine months the units are ready for transport.
Lake | Flato's first Porch House was created for the Miller family, who needed a residence to live in until they could turn it over to their ranch manager when their larger house, also by Lake | Flato, was completed on their 2,200-acre ranch in Vanderpool, Texas. The house is composed of three prefab elements, each clad in corrugated metal—a 40-by-17-foot living "room," a 28-by-17-foot bedroom with bath, and a 32-by-17-foot two-bedroom, one-bath unit. These three factory-constructed rooms, created at Ground Force Building Systems in Navasota, Texas, came complete with finishes and mechanical systems already installed, and with walls fully lined with batt insulation. Sustainability began at the factory. According to Ground Force COO Rodney Boehm, factory building by nature has a low carbon footprint, as workers come to one place, materials are sourced locally, there's little or no waste as all leftover materials are recycled, and construction systems are efficient and quick. Once complete, the units are loaded on an 18-wheel truck and driven to the site.
In the Millers' Porch House, the living-room unit and the one-bedroom are placed linearly on the site, connected by a breezeway with a movable slatted cedar wall that can be pulled to one side to block harsh winds. The two-bedroom unit lies across a landscaped courtyard. Air-conditioned spaces add up to 1,500 square feet, and with the courtyard and the carport the total living area becomes about 3,000 square feet. Because of the site-specific nature of the Porch House, each new project comes with its own set of challenges. "Some systems and materials will change depending on the locale—regional materials are one example of this," says Heather Holdridge, Lake | Flato's sustainability coordinator. "Insulation assemblies, glazing performance, and mechanical systems will also be adapted to climate conditions for each Porch House," she continues.
Boehm says many people still think "trailer home" when they hear the word prefab, but the high quality of the Porch House belies that misconception. Amy Miller agrees. "The house feels incredibly sturdy and solid," she says. "It was a surprise." With several more Porch House projects on the boards, Aylor says that so far, the experiment is working.