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July 18, 2005
The two-percent myth
If you are involved in green building, you have undoubtedly heard the two-percent myth: Green buildings cost about 2 percent more to build than a conventional building. This assertion, which makes the rounds even at meetings of true believers (I attended a Pittsburgh GBA meeting earlier this year where I heard it four times from the podium) is simply silly, for a number of reasons.
First, and most important, a thoughtful design and construction team can make a building as green as the budget allows. A well-integrated team can trade costs to achieve significant energy efficiency and to produce a healthful indoor environment while staying within a capital cost budget. You can make a building as green as you choose.
Second, the 2 percent myth is based on old information. As green building practices become more common in the construction industry, hard and soft costs are decreasing. Consider certified wood. Only a couple of years ago, a builder had to work hard to identify a source of structural lumber, and then had to import the lumber from a distance. Distribution is improving, and we may soon see a distribution center in our own region.
Third, how can one discern a 2 percent difference between a building that has been built and one that exists only on paper. If you are comparing green to conventional, you are doing so with estimated costs. The uncertainty in a cost estimate done from a detailed take-off is probably greater than 2 percent (builders, please help me here). The comparison point is probably pretty far back in the design process -- it is highly unlikely that you would do a detailed design of both buildings. So what is the uncertainty in this earlier-stage estimate? Surely more than 2 percent.
If we want to counteract the 2 percent myth, we have to change the frame of the discussion. If we simply argue against the myth, we will actually reinforce it. So I have some alternative frames to propose.
1. You can be as green as your budget will allow.
2. You can probably build LEED Silver without spending more.
3. You can build green to your budget, and then enjoy the energy efficiency benefits for the life of the building.
I welcome your thoughts.
Posted by aquacura.com at July 18, 2005 09:57 AM
Comments
I built an eco office building (2400 spquare feet) in State College in 1992. One of the important constraints was to build it for the same capitol cost as a traditional building. The design process took longer and the creative processes flowed into the project. The bottom line was that we made it! We are applying for LEED Certification, hopefully in the Gold catagory.
Posted by: jack matson at July 18, 2005 07:39 PM
1. There is a reason we call them estimates. Truth to tell, we couldn't afford to build your projects at all if the deviation were only 2%.
2. I recently completed a building that was post bid stuffed into the LEED process. Final cost performance was well within our model.
Posted by: Mark Lambdin at July 19, 2005 08:13 AM