Sunday, March 8, 2009

The Value of Value Engineering - Part 4

Recap - Parts 1-3
So to date, I've talked about paradigm shifts, easy buttons, LEED, sites & place and water. This week, energy. Generally it's a hot topic –no pun intended. And I am not talking only about our need for energy and its effect on climate change, although indeed, our energy needs are responsible for a good amount of what’s causing our climate to shift perhaps much quicker then it would were Nature left to her own devices. I am talking about more than this, the fact that how we’ve designed and built buildings has contributed to it, as well as other environmental degradation, in a disproportionate manner than were we to have designed and built better.

Who needs energy efficiency when you've got AC?
For the most part, our buildings are not energy efficient. Granted, they are better then they used to be in some respects, but still, they are nowhere near where they could be. In spite of our knowledge of dwindling resources -we’ve reached peak oil, we only have about 300 years of coal left, if that, we still prefer to build only to code, versus increasing efficiency to various percentage points above code, as the LEED rating system requires. At minimum, LEED requires that a building be 15 percent better then code –ASHRAE 90.1-2004. But even reaching this level can be a stretch for many, as the cost seems prohibitive.

We also seem to have convinced ourselves that high tech is better than low tech. By that I mean our buildings have little relationship to climatic factors like sun, wind, and climatic regions –there are four distinct ones, cool, temperate, hot-arid, and hot-humid. Instead, we design with little to no regard for how these factors can help reduce energy use, and the building is an object in the field. After all, we can heat and cool the building with HVAC equipment.

High-tech does not an efficient envelope make
Take Philadelphia’s newest tower as an example. The Comcast Tower, the most recent pride of Philadelphia. It is a beautiful building, and is in fact, a LEED Core & Shell Certified building. But it’s all curtain wall –glass and aluminum frame. At best, the entire building is an R-value of R-6 to R-9 –if they used one of the highest quality aluminum curtain wall systems available today, which would of course be, very expensive. If not, the value would hover around R-4, at best. And how about its response to its orientation to N S E W. Is there any difference? None. The glass is the same, the shape is the same. The result of all of this? A heating and cooling nightmare. In fact, in any fully glazed building, the southern and western exposures often require a certain amount of air conditioning even on cold sunny days, to maintain a comfortable temperature.

Accept our repentance

In reality, any building must balance thermal comfort, energy efficiency, and light quality with views, daylight and connectivity to the outdoors. As lovely as it is, think about all of the energy required to heat and cool the Comcast Tower. No matter how efficient, it is still requiring way more energy than would be needed had the building been designed to respond to different orientations, and had properly modulated window area with wall area, thus achieving light quality, daylight, views and connectivity with thermal comfort and energy efficiency.

In addition, buildings are also directly related to one of the most environmentally destructive mining operations today, mountaintop removal, which is most prevalent in the Appalachians. Now it is called mountaintop removal because literally, the tops of mountains are blown off to extract the veins of coal (you can read more about energy and mountaintop removal
in this post). And a great majority of the coal used at our power generating stations comes from mountaintop removal, the power that generates our HVAC systems and provides lighting for our massive stock of inefficient buildings.

And where, where is the value in any of this? Where is the value in seemingly endlessly scarring the landscape for resource extraction because we can't seem to design more efficient buildings, even with LEED? Where is the value in blowing apart mountaintops, beautifully and lovingly (and yes, sometimes tumultuously), crafted over millions of years, to generate power for these inefficient buildings? What will we say after the last vein of coal is extracted, the last drop of oil and natural gas is extracted and we turn and look at our built environment, our legacy?

Accept our repentance, Lord.

1 comment:

Nils said...

Sara - great post. Energy efficiency is my particular hobby horse, and in fact it's my big gripe with LEED. This is being recognized by the USGBC, but it can't happen fast enough. I think you've looked into the Passive House standard - it's an example of how you can go deep enough into value engineering to actually pop out the other side of the cost barrier. In the Passive House case, once you get the house efficient enough, you don't need a furnace, so the savings from no furnace fund the energy efficiency.

I've written a lot about energy efficiency on my blog, Keeping The Lights On, btw. It would be great to get your feedback, particular on this article about local code changes to encourage energy efficiency.