Another Opinion: Prefab is Not the Answer to Affordable, Modern and Green Homes
by Lloyd Alter, Toronto on 09.17.08
The 100K House
Chad Ludeman, developer of the 100K House, has looked at the prefab industry closely and concludes: "I just don't believe it is the best way of delivering modern design to the average new home buyer." He writes a guest post at Jetson Green that is thoughtful and thorough. He disputes most of the claims made by those promoting modern prefab (including me):
1. Prefab is more Affordable
2. Prefab produces less Waste
3. Prefab takes less Time
4. Prefab is more "Green"
He rips into each of these and makes some very good points. However Chad has a real advantage in his timing; prefab costs are fixed, with high capital costs and relatively constant labour costs. Four years ago a carpenter, if you could find one, earned $70K a year; they don't now. A conventional builder needs little more than a pickup truck and a nail gun to get into business, so in hard times the prefab companies cannot compete. In the last housing recession just about every prefab company in the States and Canada went bankrupt because of this, and it is likely to happen again. Advantage Chad.
However there is still an argument to be made for each of his points:
More Affordable. We are starting here because it is the easiest to disprove, and is also the main reason that many start looking into prefab. Unfortunately, most find, after weeks of research, that they just cannot afford any modern prefab unit on the market today.
I would agree that prefab does not scale down well. Because of the fixed costs of overhead and the crane, at a thousand square feet it is almost impossible to do a prefab as cheaply as site built. And of course, we don't like to promote houses that are too big.
But I spent four years in the business of designing and selling prefabs and I can tell you that people's expectations of what it should cost are completely unrealistic. They see vinyl clad carpeted prefabs at a hundred bucks a foot and demand that price for modern green prefab, even though the cladding, windows and flooring all cost over twice as much.
North Americans have a disease, pricepersquarefootitis, that drove the McMansion boom (air is cheap, so blow it up more) and makes small modern prefab look expensive. Nonetheless, for small houses, Advantage Chad.
Less Waste. Since prefab is built in a factory they claim to create much less waste by setting aside their scrap and reusing it in other projects. What they do not often advertise is that their structures use 20% - 30% more raw materials than stick-built homes in order to withstand transportation.
Absolutely true. But on a conventional construction site, studies have shown that 30% of the materials are wasted through theft, water damage, or just thrown into the bin. I would rather have the material going into making my house stronger and quieter than into the garbage.
These days, one needs armed guards on a construction site to keep people from stealing the wiring; a prefab gets delivered with the front door locked. This situation is only going to get worse. Advantage Prefab.
Less Time. Most prefab companies will claim that there are significant savings because the construction process is much faster than a traditionally built home. The site work can be done while the home is being built in the factory and the actual physical build time on the manufacturing floor is only a few short weeks. However, in practice there may be months before that process, and months after, that greatly lengthen the time before the home is ready to be lived in.
Here I profoundly disagree, primarily since Chad says "With site-built homes often going up in 4-5 months where is the time savings in prefab?"- And when did a site-built house go up in that time from start to finish? The six to twelve months that Chad claims prefabs takes includes design, building permits and probably all deficiency cleanups. I have built prefabs where the house started construction in the factory on the same day as the foundations were poured, and the house was set two weeks later. Allow two weeks per module for finishing on site and you are done. Advantage Prefab.
More Green. We'll throw this in here because "green" is hot now, so the prefab companies are jumping in and claiming superiority again in the green realm. Much of the green claims in prefab come from the lower waste myth that was dispelled earlier. The new one that we've been hearing more of lately is that the insulation is installed to better standards than site-built homes because of the superior labor and inspections put in place by the factories.
I could point out that the vapour barrier is as important as the insulation and in a prefab, where they build from the inside out, it is far more likely to be intact. I could also point out studies that show how much fuel is saved by not having those monster pickup trucks that every construction worker drives. But really, Prefab is just a house built in a factory instead of a field, and it is only as green as the materials in it. Advantage Neither.
In the end, at this time, I would have to call it a tie. If Jim Kunstler is right and the American suburban experiment is dead, then there will be lots of cheap labor about and prefab is pretty much dead too- it will never be competitive.
But at some point when the housing market returns and there are banks that lend money, people are going to demand the quality and consistency that comes from a factory. That's why cars aren't built in driveways.
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He appears to be referring primarily (perhaps not exclusively) to "modern prefab" -- ie., the high-style stuff being done by famous and semi-famous architects/designers.
Drive through any rural community in the US; chances are many (even most) of the homes you see are prefab. There's a reason for that, and it's not because they're rich.
Pah. You want a new house? Roll up your sleeves & build it yourself. Use local materials as much as possible - logs, cob, strawbales, adobe, etc. Want to build underground? Try Mike Oehler's Fifty Dollar and Up Underground House. Want to do stick-built anyway because it's familiar? Try here, they have good simple plans for a reasonable price and a supportive group of people to talk you through the building process.
okey dokey... but how is theft linked to those materials being wasted? Of course there are the ramifications of replacing stolen materials and the (environmental) cost that incurs, but just because someone nicked it doesn't mean they aren't using it. Job sites the world over inadvertently sustain low income housing maintenance this way and the cost of theft is factored into the price of the building materials at the outset of construction.
I don't know if you should really keep score as if it were a tennis game and each point had equal weight. This is an important, complex subject.
In the first point, which doesn't have a title, you are forgetting that there are many very large, national or regional builders in the U.S. with heavy fixed costs GREATER than those of a pre-fab builder. There are lone guys out there with a pickup truck building houses but that is by no means the entire field.
That also brings up the point that you can have mass-production on-site as well as in a factory. The large developers build subdivisions. The houses are merely an on-site mass-produced component of their real product, the subdivision. Same thing with an apartment or condo complex or building.
As far as affordability, pre-fab comes in a range of quality, as you point out. Given a particular quality, pre-fab should be less expensive than stick-built. Giving the point to stick-built because Americans want cheap, tacky houses doesn't make sense. As you point out, you can make pre-fab cheap & tacky, too--it's called "modular housing", before that "mobile homes", before that, "trailers". My bet is the next term to fall by the wayside will be "pre-fab" as it goes from being the preferred term to a signifier of the cheap and tacky. (Sorry, I don't know the next preferred term.)
Complaining about Americans having "pricepersquarefootitis" is silly. Europeans and South Americans have "persquaremeteritis". Steak is sold by the pound but everyone is aware that there are different cuts and grades of beef. Yes, people need a way to compare prices even if the products are not identical. So dishonest homebuilders and real estate agents need to stop inflating the square footage. I have seen apartments where the square footage was overstated by more than 50%.
The really big thing that is being overlooked here is that the vast majority of stick-built homes are not significantly different than houses being built a hundred years ago except by way of being of lesser quality. You can't really build your own automobile on-site but you can build your own house on-site? Sure, if you build a pre-industrial revolution dwelling. So most American housing is cheap and poorly-constructed, if expensive. The real issue is the product, not whether it is mass-produced or where it is made. Get the product right and the "proper" way of getting it made will be easy to see. Or make a case that traditional dwellings are preferred and continue to have barn-raisings. (There's been a big trend to hiring Amish and Mennonite homebuilders, you can't find one not already booked.) Or allow both to co-exist.
And yes, quality control (inspections and labor supervision) can be better in a factory than on-site. And stick-built houses are exposed to weather during construction. There are little things, too, like the foundation trench being filled with garbage and construction debris and trying to get a contractor to send someone back to take care of a punch list or having your existing trees damaged.
In regards to quality control, there really is no promise of it being better in a factory versus the field. I'm in the commercial side of things, not residential, but from my experience we have had to keep a much closer eye on the construction quality of prefab than on stick built contruction. Often, we or the prefab company have to have onsite workers to repair what was not done properly in the factory. The biggest benefit we have seen, again from a commercial/retail perspective, is that the store is open much quicker, and the sales gained from that earlier opening make up for the extra cost of the building and labor about 90% of the time.
In my view, seeing the extra hassles we have to deal with in order to get a prefab building, it is much simpler to go with stick built construction. Is it greener? I think that is a much bigger question than what has been discussed in this article.
Lloyd,
Thanks for the educated critique of the post. I agree with a lot of what you are saying. I wanted to point out that I am not intending to pit prefab against stick built, but rather suggesting that there is a way to meld the best of both techniques into a hybrid approach. I discuss this in more detail in the second half of the Jetson Green post.
In the hybrid approach, prefab is encouraged in Structurally Insulated Panels that reduce onsite waste and provide a superior envelope in terms of energy efficiency than either stick built or prefab can currently deliver. SIPs are readily available in every state today.
The second area prefab is encouraged in the hybrid approach is in prefab interior framing or even prefab kitchen/bath/closet modules that can be manufactured locally in any city. This is not readily available today.
The hybrid approach really is being accomplished in many ways by production home builders, which is a good point that you make. The problem I have at the current time is that most if not all are building homes that are not very sustainable or energy efficient. These homes are also devoid of architectural significance in most cases.
M. Anderson is also correct in the type of prefab I am referring to. Non-modern and non-green prefab can be very cheap and very fast.
Thanks again for the post. For the record I am a fan of prefab and think there is a lot of great stuff out there. I just don't think it is the ultimate method of delivery for affordable, architecturally significant and green homes. There is a better way and these discussions are what spark others smarter than myself to figure them out and put them into practice.
I would argue that most of the prefabs out there are really just the same home with the same technology built off site. We will really see a benefit from factories when we create real factories, not just off site sheds. This will mean a complete change in technology where materials show up at the factory in bulk, not in easy to handle chunks such as 4x8 foot plywood. Factories will be fully automated will not have people swinging hammers/nail-guns like on a job site, it will all be robotized. Jobs will be planned out far enough that there will be no scrap (some factory & kit home mfgs already do a good jab of reducing scrap thanks to ling range forecasting, but it increases lead-times). Henry Ford had his waste down so low that he specified the exact size and shape, and hole location of every board used to ship engines to his model T plant so that they could be reused as floor boards in the trucks he sold. And I would not expect to see any material used in current housing to be used in a factory house. The building tools may look more like ink-jet printer than 2x4s and hammers. The problem with this vision is the up front cost. To build a factory would cost on the order of a semiconductor plant, say $US 1 billion after a decade of R & D. The cost of quality green homes would be much less per square foot than current cost. The ROI would make this a good investment, but I doubt anyone with the cash has the courage to make this bet.
Isn't there already a glut of housing stock in the US? Prefab or conventional, either way is using up new resources.
In my effort to be green, I've purchased a 100+ year old house that needed some fixing up and am in the process of bringing it to modern standards through insulation and efficient heating & appliances. So far, through careful demolition, reuse of materials, and recycling my waste when I can, I've only sent about 2 yards to the landfill (old linoleum, mostly).
Sure, people aren't going to look at it from the street and pat me on the back for being green, but if all you really want is to appear green you should buy a Prius and try not to think about where the batteries come from.
I believe we are in a situation where there is too much housing available for the demand.
It is sad to think that there are areas of brand new ghost towns that might get bulldozed.
I wish there were a way to get more people into the existing houses that are standing and run them efficiently.
Too bad these things can't be just dismantled and put up where the demand is ... re-fab.
vsk
Isn't it also a question of which will last longer? 60 years ago, I would have said site built, no doubt. But, with the absolute shoddiness involved in the construction of the average site built house today, I'm not so sure.
I have on many occassions in past here at TH expressed my misgivings about pre-fab construction, and Chad has, from what I have read here, put forth many of those misgivings I have. I basically agree with his ultimate conclusions. And I have to especially agree with his opinion regarding SIP construction. It is better than pre-fab and better than stick built because it takes good aspects of both and does away with bad aspects of both.
After going to the show the Pre-fab show at the MOMA I asked the question: "Why don't pre-fabs seem to work?" and wrote about it here...
http://dougist.com/index.php?p=28
Doug
www.dougist.com
I like your style.
Thanks.
Elizabeth B.