We have so little waste in this type of construction that we didnt have to use any waste removal method other than our curbside rolling municipal garbage pick-up container.

What concrete scrap we have generated, we have found others who want it for bulkheads or fill in their own projects and have been willing to come pick it up themselves.
This method of construction is not cheap, but then, neither are most of the wood based modular homes I see in Dwell Magazine or similar. Plus our house will be basically maintenance free from here on out. So many people are interested in what we are doign that I photo journal the construction on http://www.ConcreteCottage.com

Nichoel Farris
American Home Sales
Auburn CA 95603
530-885-4555
http://www.ecomanufacturedhomes.com

Now, if you measure the energy used to build a house vs. that used to run the house, the energy to build is about equal to the energy consumed by the house in 5 years. So over the life of the structure, perhaps 100 years, a structure with lower operational energy use will probably be the most green, if one took the time to do the analysis.

If I were to draw a consclusion from my research, which has covered many areas and conflicting sources, the greenest thing you can practically do today on a production – affordable – basis is to build a wood frame, blown insulation structure with a low framing factor, the Energy Star checklist for thermal bypasses and sealing; with a high efficiency properly sized cooling and heating plant, that is built on a slab with south facing windows to capture some passive solar radiation for heating. All the other components in the house that use energy have a short life and can be replaced when better items arrive. The shell is hard to change later, so put the money in the shell, and reduce operational energy use for the life of the structure. Be sure to include connections on the roof structure and the plumbing system for solar hot water heating, and electrical connections and structural mounts for solar electric panels.

Interestingly, about 40% of the energy an average household uses is on transport. So moving the house where common services can be acquired on foot, and where there is a public transit option, can save a huge amount.

Build green: reduce space conditioning energy demands, reduce transport, prepare for solar water and electric; everything else is lost in the weeds or will be improved over time as technology improves.

Clearly, methods of prefabrication, whether modular, ICF, panelized or other kit-built cannot be easily rationalized in any market if the manufacturer is boutique in nature or building one-offs. The only instance where modular building, for instance, even approaches a sensible choice for one-off projects is the selection of a mosly unmodified catalog design. Prospective homebuyers in more rural areas often choose modular (as opposed to ‘manufactured’ homes, which of course are of the mobile home variety mounted on a chassis and built to HUD code rather than national standard codes) because rural mortgage products are more conducive to this industry. Rural areas are very often without the bureaucratic entaglements of municipal jurisdiction, and coupled with the reality that most manufacturing facilities are in outlying or otherwise rural areas the transport is usually shorter. Without an economy of scale, any means of prefabrication will struggle to convince owners or builders of its value when compared to conventional site building. ‘Sustainability’ must begin with patterns of development that beget more responsible behavior by its physical nature, and in truth no bamboo flooring, PV collectors, rainwater harvesting roofs, solar water heaters, xeriscapes or geothermal exchange systems will ever make a ’sustainable’ difference if patters of behavior are not ’sustained’.

Is prefabrication inherently more sustainable than conventional building? Probably not- in fact there’s likely much more chance that it will be wasteful and unsustainable than not but that’s why responsibility relies on stewardship. Expecting a prefabricated product to be sustainable by default is tantamount to handing an algebra book to an unsupervised 12 year old student and expecting the mastery of subject to simply transfer from the pages to the child’s brain. Stewardship requires effort, and I’m sure we can all agree that systems, products or methods can only be as sustainable as we allow them to be. Think of the type of compact development that architects such as Ross Chapin and John M. Campbell are building, and you can then see the viability of prefabrication as a cost effective design because of its scalability. Regarding preference of style, traditional vernacular will appeal to most and therefore endure, but crisp modernism has a growing base of appreciative consumers beyond the readers of Dwell magazine. Michelle Kauffman has been commissioned to design some affordable housing units for a developer in Denver, and the client is ecclesiastical in nature.

I remain optimistic about the prospects of prefabrication, but not because it is inherently sustainable (as some suggest) but because it allows rapid development of similar components in a controlled environment. Building more thorough, compact style multi-unit developments may offer the best chance to influence human behavior in a positive way, and without that, arguing the sustainability of one method over another just seems to miss the point.

A discussion of the term “prefab” is for the most part a discussion of the most minute percentage of the smallest portion of the building industry, the modular or panelized homes that are considered “modernist” and are built by boutique production facilities that ship very few homes per year. Our company is a distributor of more traditional, custom and production modular homes, and we work with many contractors that primarily site-build their homes and are being turned on to modular construction. I can assure you that the materials used in the “prefab” homes are more sustainable, and anecdotally I understand that the processes used in these factories delivers less waste to the landfill.

However, it is hard to believe that, as Bob quoted from one web-site, that in prefab factories “Materials are ordered in such a way that there are only trace amounts of waste instead of the tons of debris produced building on-site.” We are based in California and I find that i disagree with many marketing claims in the factory built housing industry about the way that on-site general contractors here build their houses and operate their businesses. Out of economic necessity and sometimes for more noble green purposes, the contractors build quality homes that are exhaustively plan-checked and inspected locally. Because of cost, waste is kept to a minimum by any contractor that wants to stay in business, especially those that are building more than a few homes where the waste cost line-item becomes substantial. Because of the strict contractors license laws, most homes are completed and livable except for very few flaws that the contractors come out to fix in the first year when they come up. We all know that on a case-by-case basis bad things can happen, but having seen numerous poorly built and managed modular homes, i think that it does come down to the mindset, both economic and of sustainable practices, of the on-site construction manager and developer.

The larger production modular home factories deliver less waste to the landfill for less noble reasons than the “prefab” companies. These larger companies, owned by conglomerates with tens of billions of dollars in market cap are driven to reduce waste by the market factors: Cost of disposal, cost of storage, and efficient use of materials paid for. These companies do not allow processes that let 2X4s go out the door, only to later used other 2X4s for blocking. If there are remainder cut materials they are saved for the next house, rather than needing to use uncut material on a smaller cut for the next home on the line. My understanding is that a factory or onsite builder that builds less homes has less of a need to re-use materials and to set up processes to recycle more than the bottles and cans that workers drink soda out of on the job site. This applies to low volume scattered lot site-builders and to low-volume “prefab” and modular factories. Anyone can put on their webiste that they are green. I believe that fewer pay for the labor and logistical costs of disposing of many of the materials that they could recycle.

This is a primary reason that custom building one-off homes on greenfield land starts off not being green, and has to come a long way, in my opinion by using strict sustainable materials and going completely off-grid for energy, to be a sustainable home. Greenfield development is going to happen. Arguing against it is unhelpful, and trying to sue or regulate it away (which is common in California) is a short-term solution. Eventually the population will need more housing in that area and the political forces will come into line to break the building permit or parcel splitting logjam. A better way, and i believe a realistic way to deal with this issue in the short-term here in California, is to require strict adherence with a LEEDS or comparable program which will either create the incentive to build in less strict areas or force sustainable development on the greenfield lot.

Sustainable housing must be produced not just with green materials, but must be done efficiently in a way that makes it possible for the producer to follow sustainable principles and stay in business. Many of the companies that tout their “prefab” greenness have built no or few homes, and certainly haven’t built a house for a median income level family in California that shows a scalability of their product. In my opinion, this won’t happen in the future because the look of the product isn’t mass marketable. Even with our modular product, we have built a very few homes for median income level people, because most were on a one-off basis. The ones that were built are simple, ranch style homes. Half of our homes could have been sold to median income people if the product was scaled out in a neighborhood volume of homes. To cause a change to more sustainable building, if you accept that neighborhoods on greenfield land will be built, is to build the neighborhoods sustainably. Changing the market by creating the economic environment to support sustainably built housing requires that producers and developers come together to take the risk that the production process and the finished product will meet the standards of a group like this, arrive to market at a time when they will sell, and sell at a price that shows the next developers that it is a money making adventure worth the risk. None of the “prefab” companies, in my opinion, come close to offering a solution to this problem because the “prefab” product is built in low production factories and is rarely styled in a way that a neighborhood of people would want to buy. It is a niche product at a niche price with a niche architectural style. Outside of the Bay Area and southern Los Angeles county, we don’t have many people asking for modernist styled homes.

Over-Engineering: it couldn’t be more true. If you have to be in a wood-framed building during and earthquake, i would pick a modular over on-site construction any day. I think that Lloyd’s point about the possibility and simplicity of moving a modular in the future is a valid point. Although we don’t like to have any implication that our homes are a mobile structure, it is much more easily relocated after all of the strapping and lag bolts are removed. One additional item from California is that every approved foundation plan that I have seen has a continuous stem wall at the marriage lines rather than a pony-wall. This uses much more concrete. It makes it easier to set the houses and probably makes the home stronger in an earthquake, but wastes concrete and would not be done in most site-built homes.

Shipping: the shortest distance that our homes are shipped is 350 miles, with some homes coming to California from Idaho, Colorado, and Nebraska. The Nebraska plant (we have never ordered a home from them) is 1241 miles from Los Angeles, and the plant that we order a lot of homes from in Colorado is 1,058 miles. For economic reasons, this is bad math. The common invoice is $11,000 per load.It also burns up an unbelievable amount of carbon and creates pollution that anyone but the truckers would like to avoid. Logistically, it is very difficult and inefficient. Yet to develop a market for this product in California, we have been forced to have homes built in these far-flung places. Here is the good news; based on the proof that this market exists that has come from our company and many like us in California, other factories will open closer to the market. This will reduce fuel consumption, carbon emissions, and pollution, all things that this group can agree are good things. There remains the need to distance the factory from market enough to build in a place with lower labor costs and lesser regulation, but not so much that it is mitigated by the higher fuel costs. There are such places much closer to California than Colorado and the like.

In closing, i hope that my post gets across that without a scalability of the solution with an architectural style that people want to buy, “prefab” visions of green greatness will never turn into a million Prefabhauses where there could have been a million KB Homes. I wholeheartedly support the time, thought, and efforts of the “prefab” set of companies that have developed this idea of sustainable and affordable housing. These ideas and some government regulation are affecting developers of housing in California. The next step, of which we will contribute as much as we can, is to put together the right groups of people so that successful and sustainable projects in higher volume can happen. Only then, through that success, will the copycat nature of developers come into play and change the market to more sustainable development.

P.S.I would like to thank Inhabitat for providing a forum, such that attracts this passionate group of professionals to the same table.Except for Michael V’s use of a four letter word, this has probably been the best use I’ve yet seen of the potential this medium can serve us with.
Amen

-Keith Dewey

As consumers we are being sold a crock of shit about our “carbon footprint”, “LEED”, “ECO friendly”,
“EnergyStar”, “Prefab”, etc… All this is an elaborate marketing scheme to scam good hearted and forward thinking people into buying what’s “NEXT”!

If as a species we really want to preserve our planet, the eco system, wild life and maybe a better place for our future generations we need to “STOP CONSUMING” energy, materials, fossil fuel.

America “STOP CONSUMING” all that: McDonald’s food, Walmart junk galore, Exxon gasoline and oil, IKEA forests, Toys’ R Us plastic toys, Budweiser aluminum cans, Dell landfill laptops, GAP dog fur coats, etc…

Great article BTW Bob:)

Honors would consist of 100% mandatory measures, like no vinyl for instance, or solvent based adhesives, or fiberglass insulation (that ought to get the debate going. I know its cheap (thanks to immigrant installers typically) and can be encapsulated. But it ain’t that much cheaper, it is a known carcinogen, I repeat, a known carcinogen, the “encapsulated” batts have wide open ends, workers practically never use proper protections, it’s a hazard when remodelling or disposing, and we have so many better materials that perform better). I digress..

There are too many other components to spell out here but the basic jist is to differetiate the sales talk from the builders who are walking the walk. So what if you sourced a percentage of your materials from within 500 miles if you used 25 different subs from over 100 miles away and the project took a year of them driving hither and yond? Honors would require that all sub-contractors participate in offsetting programs as a possible tenant.

For that matter ,the term green building is an oxymoron without specific guarantees that certain things took place. In fact I would argue that to really get the highest honors for green building the project would have to demonstrate a regard for land-use such that a greenfield development simply could not be considered at the highest level of environmentally conscious without some serious prerequisites, if at all. As I said it’s a new idea that is forming and needs some debate. This seems to be a particularly well informed bunch and I welcome your opinions. Greenwash can’t be stopped, but defining and constantly pushing the re-defining of the state of the art sets the bar at the top. Maybe an honors program could achieve this.