One persistent trend is energy-efficient homebuilding, the pinnacle of which might be what Sloan Ritchie, founder of Cascade Built, a custom sustainable homebuilder in Seattle, describes as a "passive house." This type of home is so airtight and has so much extra insulation and such high-quality windows that a furnace might not even be needed.
What is required, though, is ventilation, Ritchie says. That can be achieved with a heat-recovery ventilator, which exhausts stale air from the kitchen and bathrooms and delivers fresh air to the bedrooms, living rooms and other spaces, Ritchie explains.
Passive homes might be a trend, but they still account for only a tiny percentage of newly built homes.
In fact, nearly all of the 483,000 new homes constructed in 2012, the latest year for which the U.S. Census Bureau has released data, contained a heating or cooling system. Of the total, 278,000 homes had a warm-air furnace, 183,000 had a heat pump as the primary heating system and 432,000 had air conditioning.