Known for being economical in terms of space and sticker price, prefabricated homes are also boasting increasingly abbreviated build times. One modest-sized dwelling in Castlemaine, Australia took a mere 10 days to construct and garnered an esteemed sustainability marque from PassivHaus to boot. One of the world’s fastest-growing energy performance standards, ‘Passive House’ accreditation is doled out solely to homes operating on 90 percent less energy than traditional homes. For consideration, three eco-friendly parameters are paramount: thermal performance, airtightness, and ventilation. The most efficient homes use the sun, internal heat sources, and heat recovery for insulation, avoiding the need for energy-guzzling radiators even in the icy throes of winter. At just 419 square feet, the Passive House in Castlemaine, Australia (the first in the country to receive this certification) comprises a wooden frame with wool and fiber insulation and a facade clad in steel to confer a modern look. Further insulation comes from the triple-glazed windows and specially engineered seals protecting the windows and floors, which is made from an air-tight membrane called Intello. Keeping the interior snug and toasty year-round is an energy recovery system which, contrary to ordinary logic, funnels air into the house, heating it in the winter and cooling it in the summer at low running cost while also keeping moisture out. The system also tamps down heat transfer, giving the exterior of the house a u-value (heat transfer coefficient) of 0.261 watts per square meter. The lower a home’s u-value, the better its insulation. As a result, annual heating, electricity and hot water demands for the Castlemaine Passivhaus are a mere 11 kilowatt hours per square foot. Designed by Australian architectural firm CARBONlite, which specializes in prefab homes, the various sections of the Castlemaine dwelling were built off-site over a 5-day period. Once assembled on site, the exterior was erected and the building made wind and watertight that same day. The house has a mono pitch roof with an overhang to provide shade and minimize overheating during Australia’s scorching summers.
Posts tagged with "Passivhaus":
Now that LEED is old-hat, architects are starting to talk about net-zero buildings: ones that produce as much energy that they consume. Prefab pioneer Michelle Kaufmann just announced three new prefab designs that are net-zero, offering them through a partnership with Bay Area company Studio 101 Designs. The models start at 422 square feet at a cost of $66,500 ($158 per square foot). The most interesting of the three is the Ridge, a cold-climate-friendly model that is designed as an official Passivhaus--with triple-pane glazing, an air-tight building envelope, and passive preheating of fresh air--in order to meet net-zero energy goals even under more extreme conditions. LEED is often twitted for its generic, non-localized definition of what constitutes a sustainable structure; a house that doesn't consume any additional energy year-round would seem to be a pretty good definition of what is sustainable architecture over the long haul. There are two other net-zero models: the more modular Vista and another one called Contours. More information on all three is available on Kaufmann's site. Fully constructed units are available only on the West Coast, but she is also offering design plans and coordination with factories elsewhere in the US.