Low Energy Homes

An particular obsession I have is with building and underground home. Not literally for myself, of course, but as a new way for society to design it's homes to be more energy efficient. Due to the fact of constant temperature under the ground, an underground home can have inexpensive environmental controls. Also, if such a system shuts off, the temperature will drop to around 60 degrees, which would be uncomfortable, but not as bad as a house that heats up to 100 degrees.

It turns out, however, that great strides in making above ground homes virtually cost free in terms of electricity use are already here. This article talks about some Habitat For Fumanity houses that were built with special technologies(including solar panels) to make the run on much less electricity(and gas, I assume).

While the fourth Near-Zero-Energy Habitat for Humanity House was just completed, the first house has been occupied by a family of four since November 2002. The daily cost for heating and cooling this house with an air source heat pump was 45 cents. Adding the cost of operating the water heater and all of the appliances brought the total average daily energy cost for this all- electric house to 82 cents. This number takes into account $291 for solar credits that are part of the Tennessee Valley Authority's Green Power Generation program. In comparison, a conventional house in Lenoir City would use between $4 and $5 of electricity per day.

Already, builders and the public are taking notice, said Christian, who noted that many of the energy-saving features are cost-effective for all houses.

Plans call for a true net-zero-energy house to be built by the end of 2005.

I want to know how easily these technologies can be applied to an existing home, and how much they will cost. Also, I think the(rather loopy, I'll admit) underground home idea still has value in that it is more weatherproof(virtually tornado proof), and has no exterior to maintain(no painting, roofing, etc.).