Thursday, July 28, 2005

Urbana's Ecological Construction Laboratory

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When most of us think about saving energy in our homes, we think about turning down the thermostat a few degrees in the winter, and maybe adding some insulation or better sealing windows and doors against drafts. Such measures really can help to cut power bills and keep indoor air temperatures comfortable. But they allow for only incremental reductions in the amount of energy a typical house requires.

To reduce energy use in homes and other buildings more dramatically, we really need to start at the planning stage. If we do that, says German-born Urbana architect Katrin Klingenberg, it’s possible to construct a single-family home that uses ninety percent less energy than that used by a house built to conventional standards. It is Klingenberg’s goal to see housing that meets this higher standard become the norm in the American Midwest.

In spring of 2002, Klingenberg and her husband Nicolas Smith located in Urbana intending to build such an energy-efficient home together. When Smith’s life was tragically cut short, Klingenberg decided to follow through on the dream they had shared, and build the house that Smith had designed. She also established the Ecological Construction Laboratory, or E-colab, a nonprofit organization dedicated to developing, implementing, and fostering the widespread adoption of highly energy-efficient and sustainable construction techniques.

The remarkable energy-efficiency of the house that Klingenberg built and now lives in is achieved by use of a design and construction techniques based on two simple objectives: minimizing thermal losses, and maximizing thermal gains.

Thermal losses are minimized by sealing the home completely against air leaks, and super-insulating the walls, floor, and ceilings, so that they prevent the transfer of heat up to three times as well as typical new construction.

Thermal gains are maximized by grabbing all of the free natural heating and cooling available. The house’s southern exposure is made up almost entirely of triple-pane windows, so that in winter, when the sun tracks low in the sky, the floor is warmed during the day and then slowly releases heat overnight. Klingenberg’s house also uses a highly efficient air exchanger for ventilation, which provides a constant flow of air from the outside with minimal loss of heating or cooling. Air coming into the exchanger is also conditioned by passing through an “earth tube,” a hundred-foot-long loop of plastic pipe buried six feet below the ground, where the temperature is a constant fifty-five degrees. Klingenberg’s house has no furnace; at the coldest times of year a heating element similar to the one in your hairdryer provides all the supplemental warming that’s needed.

Are you curious about the extra investment required to build a house that’s so energy-efficient it doesn’t need a furnace? Klingenberg estimates that her house cost roughly ten percent above the price of conventional construction, an amount that can be recovered in five years or so of energy savings. Once that initial investment is recouped, all of that money not spent on energy is money in the bank.

The idea behind Ecolab’s current project, a four-bedroom house to be built this year with financial assistance from the City of Urbana, is to extend the benefits of living in a super-energy-efficient home to a low-income family, and to demonstrate that such construction is viable right now, not in some distant future.