With the current concerns about energy usage, the cost of oil, and comparing the size of your carbon footprint to everyone else’s, it is no great surprise that we’re seeing the spread of passive homes across the globe.
Passively heated homes are designed and built with concepts and materials that allow them to not usually require an active heating or cooling system; some passive homes do require a small amount of active heating if they are located in areas that are above 60 degrees latitude because of colder temperatures and reduced amounts of sunlight in the winter. The vastly reduced amount of energy required to heat or cool a passive home translates nicely into a far reduced carbon footprint due to less use of resources and less out of pocket costs for the home owner.
Passive heated homes basically work by using a combination of techniques to keep the warmth in (or out) of your home while still allowing fresh air to circulate. This is managed by using extra-thick superinsulation to reduce heat transfer though the walls, roof, and bottom floor of the home as well as triple-pane windows with the dead air spaces filled with argon or krypton gasses, covered with low-E glass coatings, and glazed with special high R-value frames.
These passive homes also require special ventilation to help move fresh air into the home, heat it up, and circulate it. Because these homes are airtight, this is more important than in a conventional home.
Solar panels are often used on these types of homes, as well as high efficiency appliances, and sometimes earth warming tubes which capture heat from the earth.
The problems with passive homes are pretty few and far between. There is an increased cost for some of the materials needed to build the house initially, but these costs are usually offset by the greatly reduced cost of running the house. Builders need to take great care in choosing materials and finishes that give off as low of a VOC emission as possible, however, due to the reduced air movement.
In general, the costs of building these passive homes is becoming more in line with the costs of building a traditional house. As the materials and products needed to create these homes becomes more available, we can expect the costs to likewise be reduced as well.