Imagine a home so efficient it didn't need a furnace. Sound impossible? It's a revolution taking place now in Germany, not a land particularly known for its warm climate. These so-called "passive houses" are designed to be so airtight they get all the heat and hot water they need from the amount of energy needed to run a hair dryer. Through the use of thick insulation and complex doors and windows, the airtight seal allows for the circulation of existing heating through a special ventilation system. And forget the idea of everyone wearing sweaters. The circulation of existing heat allows for all rooms to be one uniform temperature with no cold tile floors. Passive houses don't cost much more to build than conventional homes. The only downsides? Site selection is important. Also, passive houses allow for 500 square feet per person. Comfortable and cozy, but not necessarily a mansion.
Passive heated homes have been around for a long time. Tight has been around a long time also. Heat recovery ventilators do a great job of changing out stale indoor polluted air. Most buildings are poorly insulated. Most common insulation used in the US today is still Fiberglass which makes wonderful air filters for you air conditioner. Lots of other products that provide superior performance.
Likely if one looks at the materials that are used in this German home.. will likely find it its walls are a Hebel block style product. As much as 14 inch thick block that provides a whole wall insulation value over R30.
Blown in foams over R60... for the roof.
Site with lots of windows on a southern exposure. Bingo.. passive heated home.
Thanks for the insight. I always get a little concerned when someone says "airtight" as there are so many cases of asthma and allergies nowadays, that we need good ventilation to help reduce/prevent this buildup in our homes.