In homebuilding, innovation in materials technology and energy efficiency is everywhere, but construction methods seem always to lag behind as many contractors stick to the familiar and sometimes the cheap. The Guardian reports that choosing a home has become “as simple as picking furniture from the Ikea catalogue” for residents of Nijmegen in the Netherlands, where a neighbourhood of affordable architect-designed kit houses has just been launched. If you can’t afford pricey designs that does not mean settling for generic or uninspired aesthetics, inefficiency and mid-grade craftsmanship.
Author Sheri Koones champions this alternative path – prefabricated housing – that she has been promoting for years in a series of books about this option. The latest is “Pre-fabulous and Almost Off the Grid,” which features more than 30 homes built using some sort of prefabricated components.
Aimed at first-time buyers, the city’s “I build affordable in Nijmegen” initiative (IbbN) has paired 20 architects with building companies to produce about 30 designs – from detached timber cabins to redbrick terraced houses – with a construction cost of as little as €115,000 (£97,400).
Anyone with an annual income of between €30,000 and €47,000 is eligible to apply for the IbbN loan, while all costs are fixed from the beginning, removing the usual danger of ballooning budgets and long delays when building your own, untested house. Designed to be manufactured from prefabricated parts, in close collaboration with the builder, the flatpack kits are delivered to the site and can be assembled within six to eight weeks.
“Since the economic crisis, both architects and the city are trying to find new ways to build houses,” said Elsbeth Ronner of LRVH architects, a young practice that has designed one of the house types, a straw-bale eco-house inspired by local haylofts. “There are few developers willing to build, so the city is selling plots directly to the residents and letting them do it for themselves.”
For young architects such as Ronner, whose practice has so far only worked on refurbishment projects, the scheme also provides an opportunity to get into housebuilding. “It is difficult to approach potential clients when you haven’t built anything,” she said.
“People always think working with an architect will be more expensive and take longer, but this way they feel more secure. We’ve always wanted to make a really cheap, sustainable house and this gives us a great way into the market.”
Of course, prefabricated and modular housing has been around for decades, though for most people, the terms conjure cheap or unappealing structures such as mobile homes. That’s part of what Koones would like to correct. Far from being shoddy or generic homes, prefab designs can be refreshingly original (or period-style for traditionalists) and their build quality can easily meet even high-end conventional homes.
The prefab “pedigree” can come in varying degrees, from nearly complete modules trucked to the site for final assembly to just major components, such as timber-frame sections or structural panels, that are produced off-site and brought in as building materials. Koones has explained the advantages in her earlier books but recaps them here:
· Fewer weather worries: Fabricating sections or modules of the home inside a factory or shop building means materials stay clean and dry, and typically reduces the on-site construction time to mere days for getting the home weather-tight. Eliminating rain delays, temperature extremes, wind issues and other weather-related problems not only saves time and money, it helps prevent mold and rot-issues from rearing their heads later.
· More consistent quality: Workers building wall sections indoors will have the advantage of using assembly platforms, alignment equipment and other big gear an on-site crew must do without. They’ll have more tools to process lumber and other materials to more consistent dimensions, which means a better fit as everything is put together later.
· Less risk at the build site: Having fewer delivery trucks and smaller work crews can reduce damage to the building site, and closing the house up quickly helps deter vandalism and theft of materials.
· Less waste: On-site framing crews often generate a lot of scrap lumber and plywood that gets tossed aside randomly. When they need cutoffs or remnants, most consider digging through the pile as a waste of time, so that material sits to degrade in the weather, tempt vandals or be hauled off to a landfill. The planning that goes into prefab design and construction means most of that “waste” material will be stored inside and used later.
Aside from these virtues, prefab homes now can boast levels of energy efficiency that conventional structures are hard-pressed to match, and the homes Koones chose for this book highlight that advantage. More coordination and precision during the building process means insulation can be integrated into components and sub-structures rather than added on site.
Other energy features such as solar panels, geothermal furnaces or in floor heating systems also add efficiency and can be better integrated into the home. Some of the houses featured actually produce more electricity than the occupants use and return it to the grid, thus earning the owner a small monthly income.
Koones’ enthusiasm for prefab homes is easy to understand, as is her frustration that more builders don’t work this way. Part of that reality is just old habits, and part is simple economics. Most contractors can get by with a pickup truck full of portable tools, while a shop for producing prefab structures is a much bigger upfront investment. Eventually, more builders will take that leap, though, and their homebuyers will follow. Books like this will make those decisions easier.
“Prefabulous and Almost Off the Grid” by Sheri Koones; Abrams: $24.95; hardcover, 240 pages;
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