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More Building Science
I’ve been absent from the blog for about a week. My apologies. I was traveling and studying for the LEED AP exam, which I took on Monday this week and passed. I have since been recovering. I’m glad it’s over, and I am looking forward to enrolling in the LEED AP+ program when it comes out later this year. The test was pretty much what I had expected, and I’m definitely glad that I studied.
So on to the next topic at hand. Over the last few months, there has been a fair amount of hubbub about the true impact of LEED on energy efficiency. Some of the key players in the brouhaha have been Joe Lstiburek, Henry Gifford, and Brendan Owens at the USGBC. It all stems from a study that was released by the New Buildings Institute of the energy performance of LEED-certified commercial buildings.
On the one side, the study shows LEED commercial buildings to be more energy efficient than buildings in the Commercial Buildings Energy Consumption Survey, which is issued by the federal government every four years. On the other side, some folks feel that the report’s data was improperly analyzed and that the data support the contrary, that LEED buildings are, on average, energy hogs. (An aside: This argument stems from a commercial buildings study, but it ties directly into the residential sector, as I will explain.)
Now folks, I’m a scientist by training (biologist, to be more accurate). As I have said before, I look at most things through a scientific filter. I have only a B.A. degree from an excellent institution. I’m no Ph.D., engineer, architect, or any of the like. That said, I would like to take a step back and look at this argument from another point of view (I would love for you to get involved by posting your opinions here as well). So, I am going to dissect the issue and try to explain all the viewpoints. It would be impossible for me to do that without sharing my own opinions, so I will toss those in periodically. If this is as riveting to you as it is to me, please let me know that as well.
There is an extreme urgency in this nation to solve some major issues. Economy, climate change, loss of habitat and its biodiversity come to mind. More than ever in my lifetime, we as a nation need to agree, or at least “constructively disagree” about the major problems that we face. We have a great opportunity during this current reality check to hit the reset button. If we can’t achieve the greater good of energy independence and environmental protection because of squabbling, then shame on us. Hence the title of this blog post.
In the next few entries, I will be looking at the issues on both sides of this argument to try to quench the conflagration, or at least bring it under control, and to explain to you what this means for builders and trades for adaptation to the current market.
Sometimes, change is good. Sometimes it is brought on by unforeseeable (by most people) circumstances, but with change and economic instability come opportunity. What we do now with that opportunity is of paramount importance. Everyone in the green-building community wants the same thing, I think, especially now that we have all had a big dose of reality.
So let’s start at the beginning. 4.6 billion years ago…
Maybe that’s too far back. How about, between 400,000 and 250,000 years ago, Homo sapiens evolved…
Nope, too far as well. The Industrial Revolution…
Damn it, last chance, but I think that I have properly framed this conversation. On March 4, 2008, the New Buildings Institute released a study entitled, “Energy Performance for LEED¯ for New Construction Buildings”. The New Buildings Institute is a nonprofit with a reputable board of directors that works with entities to promote energy efficiency in commercial buildings. The study, funded by the USGBC, states that its results support that LEED NC buildings demonstrate substantially improved energy performance when compared to the Commercial Buildings Energy Consumption Survey.
Here’s where the crux of the argument lies for the folks that dispute the study’s claim. The study invited all LEED NC certified buildings to participate (552 buildings). Participants were required to have at least one year’s energy usage data, and 121 buildings provided the proper info. Here’s the kicker: The 21 bottom-performing buildings were omitted from the comparison. This released the hounds. I personally think that there was a good reason for the removal of these outliers, which I will discuss in the next blog.
As I mentioned earlier, I want to hear your opinion. Next blog, I’ll dive deeper into this choice, its effects on the findings, and the rebuttals. Until next time, cut off some damn lights in your house.
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4 Comments
here's an idea: let's rate building perfomance
Energy conservation is based on science and "actual performance" (how's that for redundancy?). The solution is very simple: If the USGBC wants to regain any shread of credibility in this area, it should have a totally separate rating system based only on efficiency. The initial rating would be based on a predictive model/design and would be given at the time of construction. Then the building owner would be required to monitor actual energy performance for a period of years, after which time the rating is either confirmed, adjusted, or revoked. Performance is performance afer all.
Street Cred
I'm not convinced that the USGBC has truly lost credibility in this exchange, as I will explain in my subsequent blog posts. I'm not speaking for the USGBC, but I would think that they do not want to get into the business of creating energy efficiency metrics or models. I wouldn't think that they would want to put resources into redundancy, since there are reputable resources already in existence. Namely ASHRAE and EPA's Energy Star. There is a point on LEED NC available for Measurement and Verification. I suppose that the case could be made for that credit to shift that into a prerequisite, but there is a cost factor to consider. How much is too much to spend up front before you loose a portion of projects that decide they cannot afford to do LEED. I've heard from so many that want to build to LEED standards, but not pay for the actual certification. When the oversight and verification is absent from the green building process, that increases the temptation and chance for skimping on green and fudging data. I am a HUGE proponent of third party inspections. It keeps everyone honest.
On the residential side, I think that more can be done for verification of performance. Energy Star is great, but after the HERS rating, the keys are handed over. There could possibly be a measurement and verification credit, or performance verification could just be a Innovation in Design point. Again, there is a significant cost to consider. It's easy to monitor utility bills, but there needs to be a plan of action if the bills are higher than anticipated, followed by the necessary steps to resolve the issue. From a contractor's perspective, I would imagine (and have experienced) that there would be issues around subcontractor call backs on those sorts of things. The crux of the issue is that I needs to be done right the first time (which requires education). The envelope needs to be dealt with properly when the walls are exposed, the ducts need to be sealed at rough in, HVAC sized properly, and before all of that, the house needs to be responsibly sized and sited. I have made plenty of mistakes that I have had to go back and fix, which is inevitable and also no fun, but they are also learning opportunities.
There's a lot to consider when placing blame in these sorts of debates, which takes lots of energy. My point in this whole series is that let's use that "blame game" energy more constructively to build better homes (which requires education). We are making progress here and we have an unbelievable opportunity in front of us to create jobs and build a more sustainable future. Let's take the bull by the horns.
I'll expand on ll this stuff in my next few blogs so stay tuned. Thanks for your comments.
The Gifford Agrument
There's a bunch of high-level back-and-forth, pro and con, to inform this discussion at http://www.buildinggreen.com/live/index.cfm/2008/9/2/Lies-Damn-Lies-and-Are-LEED-Buildings-iLessi-Efficient-Than-Regular-Buildings
efficiency ratings should be based on energy use
I'm not saying the USGBC should get into the business of designing energy models. I'm saying Energy efficiency ratings shoud be based on energy use. There is no extra cost to consider. Let's look at your residential scenario: If utility bills are higher than anticipated, that means energy consumption was higher. So at that point the energy efficiency rating (if there is one)gets adjusted or revoked based on energy use. This way, there is accountability, and there is an incentive for the builder/designer to do a good job. This would separate skillful builders and designers from others. The builder/designer would not have to guarantee performance, or return to fix problems regarding performance, but their reputation regarding high performance buildings would suffer or improve based on actual performance, not predictions. Reputation is important, and the reputable builder/designer will also explain to clients at the very outset of a project that energy consumption is also greatly affected by the habits of the people who occupy the building, thereby making the owner accountable as well. It is a shared resoponsibility, but ultimately the "rating" should be based on actual measurements. This is good for everyone.
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