It's Time to Change the Way We Talk About Prefab

©. TEAMMTL- ecocor panels delivered to the Deep Performance Dwelling

Forget "prefabricated" -- remember "Monteringsfärdiga".

After writing about the Deep Performance Dwelling, which I described as “Passive House and Prefab,” Scott Hedges of Bygghouse -- “a building technology company focused on commercializing Scandinavian approaches to energy performance in buildings” -- took issue with some of the language. Scott seriously knows his prefab and has worked with Ecocor, the builders of the Deep Performance Dwelling panels.

Scott points out that even though what we now think of as prefabrication has been around for centuries, the term is relatively new. I would add that it is being misapplied retroactively to building systems that are not prefabricated at all.

Aladdin homes prefab

A Brief History of Prefabrication/Screen capture

So, for example, many histories of prefabrication start off like this one by Martin Martiini with a Sears or Aladdin home, but they are not prefabricated; they are a railway car full of precut lumber and building components.

use of word prefabricated

© Scott Hedges

Scott shows how recent the the use of the word is, and that its use really peaked at the end of the Second World War, when everyone from Bucky Fuller down was preoccupied with building lots of housing cheap and fast, when aircraft and other factories pivoted to building the Next Big Thing.

I always thought of prefabrication as coming in two basic forms: modular, where buildings are built from three-dimensional blocks, and panelized of flatpack, where they are built from two-dimensional panels.

But, as Scott notes, they are much more sophisticated in Sweden. Just like the Inuit are purported to have a hundred different words for snow, the Swedes have words for prefab that don’t even have English equivalents.

Many of the differences between the way they build prefab in Sweden versus how they do it in North America has to do with the history of the industry in each country. In North America after the Second World War, many factories were set up to build trailers for people to live in, but they quickly learned that the 8’ 6” width of trailers was too narrow. So Elmer Frey of Milwaukee's Marshfield Homes led a campaign to get 10-foot-wide units approved, on the basis that they really only went down the road once from factory to trailer park. Soon it went to twelve feet and became known as mobile homes, and then trailer parks became mobile home parks.

These were built fast and cheap, (really fast -- when I visited a Palm Harbor factory the modules were chain-driven and I almost got run over by a moving house) and had a poor reputation. So the industry rebranded as “manufactured housing” with the same factories turning out park models and modular homes, where the boxes were stacked up on top of each other and wrapped in vinyl.

US modular splash page

US Modular/Screen capture

They have rebranded again as “modular housing” but the main selling point remains the same: faster and cheaper, right there on their splash page.

In Sweden, the history is very different. As Scott Hedges and Greg La Vardera explain in their article, Innovation in Residential Construction Systems in Sweden,

Sweden and the United States share a heritage of wood framed residential building, a result of the timber resources common to both countries. As recently as the 1970s the way houses were built in Sweden and the US was largely the same. But the global oil crisis of the late 1970s set the two countries on divergent trajectories. Sweden entered a period of rigorous innovation, improving the quality, construction efficiency, and energy performance of their houses.

There also isn’t that big a differentiation between modular and panellized housing; the same factories do both, assembling the panels into boxes in the factory.

In the US the predominant off-site method for houses is Modular. Modular also exists in Sweden; it is called Volume Element building, and it represents a smaller percentage of homes built than Panel or Wall Element building.

panels on truck

© Ecocor

It’s tough to do panellized prefab in North America because there simply isn’t enough value in a wall of 2x6 studs; subcontractors can do the same crappy wall in a couple of hours on site. But if you look at a Swedish style panel it is a very different, much more sophisticated product. As Greg La Vardera tells me, "There is much more value in these walls, and complex wall assemblies are much easier to assemble and more efficient to assemble in a shop."

And, as I noted in our discussion of Ecocor’s panels for the Deep Performance Dwelling, they are complete assemblies built more like furniture than houses. In fact, Scott Hedges tells me that “in Sweden, the firms that build houses, are organized as a division of the 'wood and furniture manufacturers association'."


© Prefab book cover

I have been writing about prefab since I started working in the industry in 2001 and it became all the rage when Allison Arieff and Bryan Burkhart wrote the book on it in 2002. In all that time, we described what we thought were beautiful, energy efficient and green buildings with the same language as the traditional North American industry used: modular, prefabricated, etc., while pretty much ignoring the bulk of the prefab stuff being built in North America.

Perhaps it's time to develop a different vocabulary, to recognize that really good, green factory-built housing is a different product. Forget “prefabricated” and get used to "monteringsfärdiga".