This House is Assembled With a Screw Gun
A French design studio has come up with a prototype for a house made from blocks of expanded polystyrene foam insulation, lengths of laminated veneer lumber and not much else.The Pop-Up House from MultiPod Studio in Marseille is a 1,615-sq. ft. building assembled on site in just four days with nothing more than a screw gun and long screws, according to a blog by Matt Hickman at Mother Nature Network.The house is designed to meet the Passivhaus standard for energy consumption and air tightness, although TreeHugger’s Lloyd Alter wonders whether it would qualify for certification. Basic shell on the cheapAs the time-lapse video at MultiPod’s web site shows, construction amounts to assembling the precut blocks of foot-thick foam and lengths of LVLs with long screws. Given the low weight of the foam, and the modest size of the LVLs, there’s not much heavy lifting involved, either.Components are assembled on what look like I-joists rather than a conventional foundation or slab. When complete, the structure consists of two rectangular wings connected by a glass-faced room that would be a living/kitchen area.MultiPod advertises the cost of the building at $200 euros per square meter, or roughly $26 per square foot, but you’re buying only a shell. While that price includes labor for assembly, it doesn’t cover interior finishes, exterior wall sheathing, siding, roof sheathing, roofing, electrical work, plumbing, or any HVAC equipment.If you don’t like the idea of using all that foam, other insulating materials could replace it, MultPpod says, including rock wood panels, cellulose, or cork. A variety of roofing options are possible.You can’t buy the house, at least not yet. MultiPod says it created two prototypes (an office as well as the house) and is looking for manufacturers to develop and market the idea. Still a lot of questionsDevelopers say the Pop-Up House concept will meet the Passivhaus test for airtightness, which means air leakage of less than 0.6 air changes per hour at a pressure difference of 50 pascals. The company, however, said by email on March 24 that no blower door tests have been conducted on the prototypes.Prospective owner/builders might wonder about how the roof and exterior walls are sealed to the weather. Here, MultiPod suggests a variety of options, including an EPDM membrane for a flat roof, and conventional roofing over purlins in cases where the building includes a pitched roof. For exterior walls, the company says, options include fiber cement panels, metal, or even the exterior insulating finishing system (EIFS).There’s also the issue of meeting U.S. fire codes, which prohibit exposed foam on the interior of a building. At least that one would be fairly simple to solve by attaching a fire-rated material, such as 1/2-in. gypsum drywall, to furring strips.For now, the Pop-Up House is in development. Whether it ever gets to market here remains to be seen.