Prefab and sustainability - all in the name of marketing

There is a lot of interest brewing lately (e.g. Inhabitat, a green building blog, has their Prefab Fridays column) in the idea of prefabrication as a more sustainable way to build.

The usual arguments supporting its "green" stance are:

- Traditional site-built houses produce a lot of on-site construction waste (extra materials, etc.) that end up in landfills whereas, with prefab, there is significantly less because materials that aren't used up at the factory just go "back on the shelf." The LivingHomes website claims that up to 40% of a site-built homes' construction materials can end up in the landfill!

- Site-built homes consume a lot more fossil fuels in transporting materials from multiple warehouses to a single site. Site-built also requires construction workers to shuttle back and forth for a longer span of time to complete the house, thus adding to the carbon footprint. With prefab, all the materials are at the factory and only the finished product gets transported, all in one go.

This is in addition to other pros, mostly economical, which include:

- Prefab allows for more precision and quality control over the manufacturing process because the units are built at a factory where state-of-the-art equipment can cut more exact pieces.
- Prefab saves time because the foundation can be laid while the house itself is being built off-site.
- Prefab modules are made indoors, so rainy days don't impede construction as much. Also, the materials have less of a chance of contamination from mold, rain, etc. so the resulting product is more healthy and sanitary.
- Prefab has to deal with more demanding loads (due to crane lifting and truck transportation) and it has to comply with more stringent national quality codes, so by definition, it has to be better (more safe, better built) than the average site-built home.
- Prefab is cheaper due to economies of scale (logic behind mass-production applied here) and centralization.

A lot of these were taken from the LivingHomes website. (It is curious, however, that the point about factory built modules having less exposure to the elements during construction, was placed under the "sustainable building practices" header in their section about modular building. I'm not sure how this is related to sustainable building. Copy-editing oversight?)

Prefabrication does seem to have a lot of overall pros (and some cons, but I won't get into them here), but the debate rages on about whether it actually is a more sustainable way of building than traditional building. Only two points above were actually directly related to sustainable practices, and even the veracity of these two are contested. So when a company promotes itself as green and uses prefabrication to bolster this image, is it being bona-fide green or is it (gasp!) greenwashing?

I found an article on Inhabitat today dealing with this exact issue. The author, a seasoned builder, contends that the relationship between prefab and greenness is overstated, and overarching generalizations such as "prefab is always a better way to build in terms of environmental considerations" should be treated with suspicion. He argues that, while it is true that, in certain cases, prefab does result in a more efficient use of material and a smaller carbon footprint, even prefab builders can be unscrupulous about saving materials. It costs labor hours to sort scrap and isolate what is still usable, so sometimes it just makes more financial sense to toss everything, even at the factory. He also contends that the gas burned transporting modules to a site can be just as much as in traditional building. Modules require a crane, which gets 2-3 mpg, so that is clearly inefficient if your site is in a small remote town far from construction resources. The module-shipping trucks also require as an escort service of several smaller trucks on the way from the factory. And factories are fewer and farther between than building material supplier warehouses, so if the site is remote, the module likely has to travel a much longer way. Finally, because of the aforementioned greater loads in transportation, modules have to be intentionally overbuilt, wasting materials.

Just judging from the miles of comments underneath the article, you can tell that this is a hotly contested matter. Some were quick to defend prefab as being almost always better than stick built environmentally (at least in Cananda?). Others, like the author, are more reserved in giving prefab accolades, saying that it is very dependent on individual cases. But the general consensus among readers and the author is that one should never take "prefab" to denote sustainable without looking more closely at the wide range of variables. All this was shadowed by the fact that there ARE companies out there who promote prefab and claim that it has green benefits when in fact the companies are not taking the steps to ensure that those benefits actually take place.

Suffice to say, in LH's case, the company is certainly promoting themselves as being extra-sustainable because they use prefabrication, but is it greenwash? Greenwash is when a company makes false claims about being green. I don't know if it is greenwash; I'm not an undercover reporter, and in the end, I don't think that even matters. For now, I still have faith that LH is a good company, with honest aims (the paper is not out to bash them, but to critique their methodology in the wider context of sustainable debate).

What matters is the mere fact that LH recognizes that the public clearly perceives an exciting, promising relationship between prefab and sustainability (as made evident by Prefab Fridays and sites like fabprefab.com) even if the relationship itself is hotly debated (as made evident by the long comments). Thus it is openly doing its best to promote the fact that it builds prefab to bolster its green image despite that its actual sustainability benefits may be quite small. (Again, I'm not out to determine how small; not important.) LH may well be just using prefab for all the other aforementioned, non-green benefits, but it has created a special section on its website for pointing out that they also chose prefab because it is green. This is a clear marketing move, showing that LH is very intent on selling a product by pleasing a perceived market sector (reactionary), perhaps more intent than they are on promoting an ideology (proactive). (I believe that many sustainable architects put promoting ideologies before selling products.) This goes to further my argument that LH plays a big role in furthering the consumerist approach to sustainability.

EDIT: I found another blog that highlighted some of the better comments from the long discussion. In particular Philip Proefrock's blurb is a good way of summing up prefab's relationship to green building.

EDIT: On another blog, there is a reference to a UK-based organization's report, which provides an empirical research-backed proof that prefabrication does, on average, reduce construction wastes by a lot (up to 90%...), and for this reason alone, the organization encourages builders to consider prefab. So the claims to greenness have footing in reality after all! I am glad, because any step towards saving waste, no matter how small, is an improvement. It seems that most of the griping against using prefab to enhance a company's "green cred" occurs when the company overexaggerates the importance of prefab, placing it above other concerns. So while the truth of certain prefab claims can no longer be contested, its relative importance in the network of strategies comprising sustainability still is.