Lower heating, cooling, & lighting costs
Passive solar design reduces energy consumption so dramatically that its widespread adoption could seriously impact national energy independence. Building passive solar is patriotic!
Our clients love their reduced energy bills. We love our own. We have designed and built two Sungarden Houses for ourselves, and so have been able to observe the close-up energy performance of our designs.
On zero degree winter nights, our interior temperatures drop to about 55 degrees USING NO HEATING SYSTEM whatsoever. This miracle is achieved entirely by passive solar design.
Of course, our houses are heated to be warmer than 55 degrees; costs are relatively small to make them a cozy 80 degrees. Our snug 1800 square foot main residence in North Carolina was heated until 2005 by sunlight and a cord and a half of hardwood. In 2005 we installed solar roof panels, which now heat our radiant floors (with backup use of propane).
On 100 degree summer days, internal temperatures in our houses can rise to as high as 78 degrees with no use of air conditioning. Humidity is a difficult problem in the American Southeast, but can be ameliorated with ceiling fans and by closing the windows in the daytime and opening them at night for cross-ventilation at night. Even with such low internal temperatures, we recommend the installation of conventional air conditioning in humid climates: we haven't yet found a more effective and less expensive means to thoroughly dehumidify our houses – a standard of comfort that most Americans have come now to expect.
Lighting is free during the daytime in passive solar houses because all main living areas are on the south, and are naturally bright. Even on the darkest winter days, artificial lighting is unnecessary.
Many people have reported that this wonderful natural light has cured their winter depression.
None of our designs have as yet been built "off the grid" – for the sole reason that our houses use so little conventional electricity. The present cost of photovoltaic whole house systems is so high that the payback period for our houses would exceed 20 or 30 years at their rate of conventional electrical use. We expect this gap to close soon, however, as the cost of conventional electricity rises and the cost of photovoltaic systems falls.
We must here note that all Americans must be vigilant in turning off lights and appliances in rooms that aren't in use – regardless of the type of house we live in. The amount of electricity generated by nuclear power plants equals the amount WASTED in the US, a thought provoking equation that doesn't even factor in the enormous amount of energy wasted by failing to design new houses for passive solar construction.