January 1995 Issue #10

Guaranteed Low Heating Bills

Bigelow Homes, a well-known builder of superinsulated houses, built about 100 townhouses per year in the Chicago suburbs during the early 1990s. The company's marketing strategy includes guaranteeing gas heating bills for the first three years and a prize for the household with the lowest bill. We evaluated the energy performance of 21 Bigelow houses using occupant surveys and analysis of utility bills.

The houses look like many other suburban homes in the U.S. While a few have sunspaces, no particular attention has been paid to orientation for most houses. Living areas range from 86 to 350 m² (930 to 3800 ft²), including basements.

Our evaluation confirms that occupants are satisfied with their houses, and that their gas heating bills are often less than half of those for comparable new houses in the Chicago area. Occupants do not feel that they have sacrificed amenities for lower energy consumption. In fact, many report improved comfort compared to their previous homes. Electricity use was not a target of conservation efforts and did not exhibit similar reductions. Small townhouses used less energy than larger houses, both for space heating and overall. Large houses used less energy per unit of floor area.

Occupants of a 2000 ft² Bigelow house can expect to save about $200/year on heating. The houses cost little more to build than standard construction. Costs of extra insulation, sealing, and low-emissivity windows are offset by eliminating ductwork and downsizing the heating and cooling system. The cost of conserved energy (CCE) is 10-20¢ per therm, while the average gas price during the study period was about 40¢ per therm. The average CCE for U.S. gas-heated superinsulated houses in a 1986 LBL Building Energy Compiliation was also 40¢ per therm.

While these houses can be called "low-heating-energy," they use more energy overall than most other low-energy houses in our current research. To decrease consumption further, the energy used by appliances, lighting, water heating, and cooling must also be addressed.

-Barbara Litt

For more information, please contact Alan Meier.

More about Bigelow Homes from Home Energy Online.

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