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LEED vs Green

by Charles Lauster Architect, P.C. on October 21, 2009


LEED vs Green

CLAblogBy Peter Kincl

What, exactly, does it mean to be Green? And why does it matter? Consider these statistics: buildings consume about 40% of all energy in the United States. Of that, 84% is used in heating, cooling, hot water, electricity, lighting, etc. Only 12% is embedded in construction. 16% if you add maintenance and renovation. That’s it, 16%, which includes manufacturing all the materials used and then transporting them to the building site. Now I’m not claiming this 16% is an insignificant number – it isn’t. But compared to the 84%, it is. If we want to make a significant reduction in energy use, we need to tackle the 84%.

For the foreseeable future energy conservation will be the single most important aspect of being Green. Water conservation is important, but water shortage problems, although serious in some parts of the west, are, right now, not as potentially devastating as the economic and political disruptions that could be precipitated by declining oil and global warming. Besides, buildings account for only 11% of all water usage, so the potential to make a significant difference is small. Similarly, recycling, renewable resources and conservation matter, but energy shortage and carbon dioxide emissions are much more pressing problems.

Which brings me to LEED and why I believe that in some ways it is more a problem, in terms of making a real Green difference, than a solution. Too many LEED buildings either save no energy or actually use more. This, although maybe on the face of it astonishing, should come as no surprise. It is entirely possible for a building to acquire enough points to become LEED certified without doing anything to limit energy use. LEED is a collection of points which a project accumulates for satisfying certain conditions, and the vast majority of these are unrelated to energy use.

For example, I am amazed that an all glass building can even qualify for LEED certification, let alone actually get it. A basic knowledge of thermal conductivity, thermal bridging and solar heat gain is sufficient to understand why an all glass building can never be energy efficient. And yet it seems quite clear (given how many of these things keep going up) that this is not common knowledge, not even, it seems, amongst building professionals. Either that, or it is knowledge being willfully ignored for the sake of marketing and/or aesthetics. Either way, it is the equivalent of building big gas guzzling SUVs. There is no way to call an all glass building Green. And yet the USGBC doesn’t seem to mind. The certificates keep coming.

There are alternatives to LEED, real alternatives that actually make a real difference. All of them have one important thing in common: a metric. In other words, they have a goal that can be measured. The measuring can be done in Btus used or carbon emissions or whatever units, but the goal has to be measurable and verifiable. Put simply, what, at the end of the day, is the utility bill?

One such alternative is the Passive House concept. The point of Passive House is to construct a building that uses only 4.7 kBtu/sq.ft./yr. for heating and cooling, and it keeps primary energy use equal to or less than 38 kBtu/sq.ft./yr. To one unfamiliar with the jargon, these numbers mean absolutely nothing. But the numbers are important because they are numbers, and because, if one is familiar with such numbers, they are incredibly low (up to ten times more efficient than an average building). To achieve such an ultra-low energy performance is admittedly not simple, but it is very much doable. There is an up-front price premium (which can be offset in the long run with savings on energy consumption). But as we build more and more super-efficient buildings, the industry will become familiar with the construction methods required, and products, such as super insulated windows, will hopefully be made in the USA and their price will come down (the windows, and pretty much all high efficiency Passive House components, are currently German).

I would suggest that being Green means a credible and quantifiable drop in energy use. It means a real reduction in carbon emissions. It means, in the building industry, dealing in a serious way with the 84%. It does not mean papering over inaction by awarding relatively inconsequential points. Olympic inspired ratings don’t mean anything. A significant carbon footprint reduction does.