When a couple of attorneys in Santa Monica first decided to build their dream home, they looked into prefab houses. But they found the options too limiting in part because their lot was fairly small — 7,500 square feet. "We really wanted to take advantage of the space that we had, so going custom was the best option for us," says the husband. However, the couple was still able to use prefabricated building components. Instead of traditional wood framing, the Santa Monica home was built using a relatively new product called mnmMod. The prefabricated custom panels are like
Lego bricks that bolt together, allowing a home to be built quickly with very little construction waste. The panels are among the latest innovations in home construction, bringing a higher level of quality control to the process. (Photo courtesy mnmMod.)
Today, the majority of homes are wood-framed — their exterior might be stucco, brick, or stone, but their bones are made of lumber. The framing is done on site and the lumber often has to be cut to the correct dimensions, a time-consuming process that generates a fair amount of waste material. One alternative is SIPs (Structural Insulated Panels), which provide structure and insulation together. Most SIPs are made of OSB (Oriented Strand Board, similar to plywood) around a core of expanded polystyrene foam. First developed in the 1930s, SIPs are now fairly common. While SIPs cost more than traditional wood framing, they save money by speeding up construction and lowering energy bills, since they have superior insulating properties.
Providing a new twist on SIPs, mnmMod panels are also a compact sandwich of structural material and insulation. Launched in 2013, mnmMod panels use light steel framing around a core of expanded polystyrene. Although steel requires more resources to produce than wood, it is recyclable and has the advantage of greater strength and stability. To date, 20 houses have been built using mnmMod and 20
more are under construction or in the plans.
Another light-steel system is Bone Structure. The company, which launched in Canada in 2005 and recently expanded to the US, has produced more than 300 homes. The pre-cut steel components enable
the large, column-free spaces that are a signature feature of contemporary homes. They are also coupled with an integrated thermal envelope for a well-insulated structure. Both the mnmMod and Bone Structure systems have thermal breaks to prevent the steel from conducting heat and cold (a significant drawback of steel framing). The prefabricated components provide a level of precision that is particularly critical for contemporary architecture. Says architect Erla Dögg Ingjadsdottir, co-founder of mnmMod,"You know exactly what you’re getting."
The companies can take existing house plans and adapt them so they can be produced using their custom parts. The systems are especially well suited to contemporary designs where high ceilings, long spans, and wide windows and doors are called for. Designs that might work for this kind of construction include
4 bed 2.5 bath Plan 64-190
, above, organized around a pool courtyard; or 3 bed 2 bath Plan 552-4
, below, with window
walls surrounding the great room and the master bedroom; or 1 bedroom cabin Plan 450-3
so called "dogtrot" breezeway between the kitchen/living area and the sleeping zone.The Bone Structure website is here. The mnmMod website is here.
Lydia Lee writes about design for Architectural Record, Sunset and other publications.