It is the dawn of a new day at Prairie Crossing in
Grayslake, a place that self-consciously calls itself “A Conservation
Community.” The hypothetical Smith
family, is committed to conservation as solution, unlike Vice President Dick
Cheney, who famously said, “Conservation may be a sign of personal virtue, but
it is not a sufficient basis for a sound, comprehensive energy policy.” Mr.
Smith takes Metra into the city on weekdays, while Mrs. Smith drives a Prius.
They live in a modest green home, built using the best passive technologies to
reduce their energy consumption. Prairie Crossing is a community that is
designed using the best planning approaches championed by the Congress on New
The streets of Prairie Crossing are narrow and the houses are built closely together, making it convenient to walk to the small town center,
The hypothetical Smith’s are hypothetically green. They have made progress towards a green future. Where a normal suburban household consumes 240 million BTU’s of energy per year to maintain the house and for transportation, the Smith’s have likely reduced this number to 164 MBTU’s.
But there are disquieting truths lying just below the surface of Prairie Crossing. Where in a normal suburban household 125 MBTU’s of the 240 total energy is used for transportation, in the Smith’s case, roughly half of their energy use is still devoted to transportation. Even more discouraging, if the normal suburban house—not a particularly green one—is built in a city, the transportation component of household energy use drops to 28 MBTU’s, bringing the overall energy use down to 143 MBTU’s. In other words, the location of the house has a far greater impact on household energy use than all the efforts and expenditures to build green and drive green.
On the other hand, if you build the Smith’s green house on an urban lot, the household energy use drops to 89 MBTU’s. Even better, if you lease or buy in a multi-family green urban building, energy consumption drops to 62 MBTU’s or 25 percent of the typical suburban household.
The energy-efficiency of multi-family housing is often overlooked. Where a single family house usually has a one-to-one ratio between interior and exterior surface area, which gains heat in the summer and looses heat in the winter, the typical apartment has at most one or two edges exposed to the weather and is surrounded above and below by other apartments.
In an earlier article, I discussed how sprawl is both an age-old phenomenon that began during the
In a variety of forms, the latest thinking about energy consumption and global warming is centered around what has been called the carbon challenge. The hypothesis is that we should as a culture accept the challenge to reduce carbon generation in a series of ever more stringent stages over the next 30 years. Carbon generation is a measure of both energy use and the pollution that scientists see as the cause of global warming. The ultimate goal is for every household to become carbon neutral. It’s clear the easiest way to respond to the carbon challenge is to move back into the city.
Urban residents in multi-family buildings have a shorter distance to travel to meet the carbon challenge. Increasing efficiency of both rapid transit and cars, combined with smarter building design, should allow these households to meet this goal. For owners of single family buildings, they will have to work harder to meet their carbon budgets —probably requiring active technologies such as the use of photo-voltaic (PV) cells to produce energy.
For suburban residents, it will be a far more difficult exercise. We can already see both the potentials and the problems. The efficiency of buildings and everything they contain are improving rapidly. The future single family house, both urban and suburban, will probably look much like it does today except it will lose much less heat in the winter and gain much less heat in the summer. Every personal device will use a fraction of the energy that is used today.
The biggest problem is transportation. Despite our best efforts, it still takes a great deal of energy to move things from place to place. Prairie Crossing is a conservation community compared to other suburban developments, but can such an approach ever meet the carbon challenge?
Published: April 06, 2008
Issue: 2008 Spring Green Issue