ENERTIA   HOMES No Fuel? No Power? .......No Problem

September 12, 2007 by Bob Feeman

One of the latest trends in homebuilding has been dubbed Environmental Architecture, and one of the companies at the forefront of that movement is Enertia Building Systems, based in Wake Forest, N.C. In a nutshell, Enertia builds energy-efficient kit homes, which include pre-cut solid-wood exterior walls, a girder-and-beam frame system, door and window frames, and heavy timber rafters.

Other components of the customizable timber homes windows and doors, ceilings, floors, partitions, plumbing, wiring and finish materials can be ordered through Enertia or provided by the homeowner.

What's special about Enertia homes, though, is that they are designed to heat and cool themselves using solar and geothermal energy. This is accomplished in two ways first, says Enertia owner Michael Sykes, by scientifically placing the thermal mass of (exterior-wall) logs in the right place.

Studies have shown that solid wood walls store the sun's energy during the day and release it at night, keeping the house warm when the outside temperature cools. Sykes uses southern yellow pine exclusively throughout his Enertia homes because it has a higher resin content than other types of pine, so it can store more energy.

In addition, each Enertia house has a built-in envelope just inside the structure's solid-wood skin. This acts as a heat path during a sunny winter day, circulating warm, solar-heated air from the south side of the home, upward through channels in the roof structure, down the north side of the house and back around to the front.

As the air circulates, it charges the thermal mass, says Sykes. In other words, the heat in the air is soaked up by the timbers, which store the heat and radiate it through the night.

Similarly, in summer, warm air is vented at the top of the home, while cool air is drawn in through low windows on the home's north side and further cooled as it circulates through the basement. This is the geothermal cooling element.

Because the energy is stored in the building skin, walls, floors and ceilings are warm in the winter and cool in the summer, says Sykes. The air path also acts as a run for cable, wiring and plumbing, so the home can be easily updated.

Most Enertia homes have a small, back-up radiant floor heating system fed by a water heater, but these are rarely used, says Sykes. We don't even install them in sunnier climates like Utah and Colorado because they're not necessary.

Because of their design, Enertia homes are disaster-resistant, and there's no need to panic if the power goes out since the homes won't get too cold or too warm. In addition, the homes have long life expectancies.

Certain models of Enertia homes can be assembled in about two weeks, with another month or two required for finishing. The homes are priced from about $54,000 to about $224,000; options such as garages and porches are priced separately. For more information: http://www.enertia.com or 919-556-2391.