Anne Arjani; Oh boy, what you're talking about is a subject that's been discussed, since we lived in caves. Probably cave dwellers did a better job of using natural ventilation for cooling and heating, than we do now, as 21st century cave dwellers.

Starting at the beginning, under ideal circumstances (which is rarely the case), any domicile should be constructed or "chosen" (as in the case of the first cave dwellers) based on how the dweller will use the natural elements to his/her advantage. As soon as a house is constructed without those considerations, every future change to the house will be a compromise, because the designer alienated the natural elements, rather than embraced them.

I know that we have simple technologies now that enable us to build domiciles in any reasonable climate that don't need mechanical Heating and Ventilation systems, to stay comfortable. Add to that the ability to boost the natural cooling and heating effects using things like fans, heat pumps, mechanical attic cooling etc.. and by using solar energy to run those things, and I cry when I drive past the vast tracts of suburban housing in America, that ignore those principals. Usually land is the culprit. When a house is 2500 ft2 and the lot is 5 to 6000 ft2, you can't use a ground source heat pump, because you don't have enough ground.

People have been building passive solar houses/domiciles, since someone noticed that the sun was warm, it's not a new idea. Look at any older New England farm house. Often the owners occupied the land for years or even generations before they built the farmhouse. They used conventional materials, so a cursory look seems to reveal a conventional (non solar) house but in reality, every beating heart that walked that land during the early years helped to develop the plan for that house.

In '02-03 we built a 2 story house in Alabama. In the woods on a 3 acre lot. Slab on grade foundation, located on the highest point for drainage. 8" concrete block walls filled with grout (pourable concrete) for the first floor, 6" blocks for the 2nd floor. The blocks were laid up flush on the outside, leaving a 2" ledge 8' off the floor on the inside, which the conventional suspended wood floor (the joists) sat on. The truss roof was a system of overlapped fiberglass bats (no thermal bridging) and vapor barriers. (One on each side because of the cold and warm climate) Outside the blocks were wrapped in 4'x8'x2" polyisocyanurate panels, which provide an uninterrupted R 15 (slightly over code in 'bama), act as a vapor barrier (vapor trying to get in and vapor trying to get out) and made the house fairly airtight, when all the doors and windows were closed. The whole house then received a locally made brick facade. The walls were 14" thick with roughly (my estimate) 175 tons of concrete thermal mass inside the insulation vap barrier system.

At the highest point in the roof trusses, two Velux ventilating roof windows (skylites) opened automatically when heat accumulated under them. Escaping air created a mild negative air pressure system in the house which was quickly equalized by cool incoming air from under the slab foundation. A whole house fan circulated the cool air as if it were cool air from the air conditioning system. Code required traditional air conditioning, but during the Alabama summer, when the thermostat was set to 76 to 78 degrees, the air conditioning didn't come on. The house was featured in an industry magazine promoting masonry products.

It was termite proof, fireproof, tornado proof, extremely energy efficient and even looked very appropriate for the site. Made from local materials, all the interior trim was milled from oak trees that I cut from the site to provide a clearing.

It took six months to sell that house. Not one of the 40 or 50 couples that came to see it had any interest whatsoever in the energy aspects. No tray ceilings? No crown molding? Are you going to put drywall over the exposed cement blocks in the living room? By the way, why are the living areas (kitchen, dining, living and master bedroom on the 2nd floor? (Answer; Because that's where the birds, the view, the privacy, the breezes, the decks and the beauty are). America needs god's blessing when it comes to housing, because left to their own priorities....