Blog Post

Reductio ad absurdum

I recently went through the scoring tool on the National Association of Home Builders (NAHB) green building website www.nahbgreen.org. The tool lets you get a good idea how your project would rate according to the National Green Building Standard (EBN, March 2009), and to plan adjustments in the design and construction process to do better. Using information about my own house was a way to simultaneously get acquainted with the standard and satisfy my taste for self-administered tests. (What's your IQ? What type of personality do you have? If you were a quattrocento fresco painter, which one would you be? Facebook users will know just what I'm talking about.) Responding to each point in a rough-and-ready way, the process took me perhaps an hour. I made a few guesses about things I wasn't sure of, but since I was pretty involved in the design and building of the house, most of the information was easy for me to come up with. Of course I wanted to score well. To meet the most basic ("bronze") level, I needed 222 points overall. I easily hit that target, with 339 points, but was well short of the 406 points needed for the next level ("silver"). And, despite the point total, my house didn't qualify for bronze, because there are point requirements in each of the tool's six areas--site development, water conservation, energy conservation, resource conservation, indoor air quality, and homeowner education--and I didn't get enough points in homeowner training or water conservation. I feel comfortable ignoring the recommended homeowner training, which could have been provided to me if I had felt I needed it. It doesn't strike me as a problem that my builder didn't tell me about termites, safeguarding the frost-protected shallow foundation, maintaining the gutters, public transportation, or local recycling programs, because termites and public transportation are rare in my town, the house doesn't have gutters or a frost-protected shallow foundation, and, having lived in the same town for a decade before the house was built, I was familiar with the recycling program. I'm sure that in many situations, however, a new homeowner would benefit from being informed about these matters. When I was designing the house, saving water was not high on my list of priorities. Maybe it should have been. It wouldn't be hard to get the additional eight points to meet the section's requirements--putting in a 1.6 gpm showerhead, a low-flow bathroom faucet, and a 1.28-gallon-per-flush toilet would do it. Too simple? Well, I could install two more Energy Star dishwashers (we've got one already), a garbage disposal, and a spray-head irrigation system with zones for turf and bedding. We missed a big opportunity by building on a rather flat site, which makes us eligible for just four points for avoiding steep slopes. If we had made the driveway a few hundred feet longer and cut down a patch of woods, we could have taken advantage of the points available for those who build on hillsides: five points for doing a hydrological/soil stability study of the hillside; five more for aligning that long driveway with the topography; and another six for using terracing or retaining walls to stabilize the slope. Energy efficiency was a major concern of mine in building this house, and it did well in the energy section of the tool, with 117 points. (Thirty are required at the bronze level.) More points there wouldn't have helped me earn bronze certification, but if I just wanted to rack up points for fun, I could put in some ducts and get rid of the wood stove. Our main heating system (aside from passive solar) is a radiant hydronic slab. Heating without ducts got us a substantial 15 points, I suppose because ducts can be a source of trouble. But if we had ducted heat, and it was really well set up, we could get up to a whopping 48 points, plus four more for an air handler. I think it's a good idea to have the woodstove, since we can use fuel we gather nearby, and the stove works even when the power is out, which is nice. But we could reap seven points for giving it up. Some other points we passed up: 10 points for carpeting; four points for an integrated pest management landscape plan (we plan to accept pests, for the most part, and the vegetable garden is organic); four points for underground parking that uses the natural slope for entrances (which would also save us having to scrape ice off our windshields); and five points for a central vacuum system. If we went all out with the irrigation system we don't now have, we could earn as many as 19 points. Okay, I'm making fun. No system is perfect, especially a new one. Still, I'd say this system has some kinks that need working out. It seems to reward tackling problematic situations with expensive solutions more than avoiding them altogether, and it promotes complexity and a superabundance of plumbing. While the National Green Building Standard is certainly no hindrance to building in a truly green manner, given that any such system gives rise to point hunting, it could result in some foolishness. I'd be interested in hearing from people who are using this standard for real.

Published March 23, 2009

(2009, March 23). Reductio ad absurdum. Retrieved from https://www.buildinggreen.com/blog/reductio-ad-absurdum

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Comments

April 2, 2009 - 6:07 pm

It would be nice if the NAHB guidlines were not so long and intimidating. They seem to dissuade most builders because of this and the measures are expensive. Perhaps first we could start with energy and then we could do some designed "green" amenities. I can do the high performance home thing, but in my town even the best builders would have one hellof a hard time reaching silver rating. If we are doing this to change these best practices to business as usuall then we had better provide for, or better yet require, some continuing education (like they do for Engineers and Architects) for our home builders. Maybe the NAHB can figure out a way to get some funding for Energy Code training and Building Science so it can educate builders abour real "Green Design".
Brad
Mid Missouri Home Energy Services
Professionally Cert.
Home Performance Contractor

March 23, 2009 - 12:33 pm

Michael, so you go ahead and do this lot and have high scores on the board and then what? Will the 'increased' value be reflected when you come to sell it? Will you get your money back? I am hearing (anecdotal) that bronze level houses with similar scores to yours were subsequently tested post construction and failed miserably. The wood burner for example is just nuts when the renewable resources are local, its off grid and with the right kind of kit you could achieve 70% plus efficiency. And then, what if this house was rented would the occupants energy manage the house to its designed specification? The public transport and recycling features equally need putting in context too, how truly energy efficient are they in practice, are they the 's' word?

March 24, 2009 - 5:45 am

Josh, I do. Try this link: http://www.icfi.com/Markets/Community_Development/doc_files/apj1098.pdf

I am a NAHB Green Building Verifier.

Stop by The Green Building Inspector for other informative and up-to-date articles, reviews and news...

March 24, 2009 - 5:37 am

Gary,
Do you have a link to that white paper that you mentioned?

March 23, 2009 - 4:12 pm

Why would you want to install 2 more dishwashers when you already have one? I'm confused at your lodgic? Was that suppose to insinuate that the Standard asks you to install 3 dishwashers in the kitchen?

The NAHB Green Building Standard is written to be affordable, practical and the approach is manageable.

The American Appraisal Institute has a white paper out that mentions that for every $1.00 dollar you trim your heating bills through pro-active green designs and construction the home's value increases $20.00. Yes...your home is worth more green.