Most homeowners and builders do not recognize the importance of floors for comfort and energy-efficiency, and they end up with homes that are expensive to heat and cool.
Floor coverings aren't really important for home energy performance. Typically, they aren't thick enough to prevent heat transfer.
Anyway, they aren't irrelevant in some cooling and heating strategies, or for radiant floor heating, or for floor comfort... And there are many criteria that you should consider when buying a floor covering: price, stain- and water- resistance, strength, look…
Many floors – over crawlspaces and basements - have service penetrations that should be carefully sealed.
That’s very important to create an interrupted air barrier between the basement and the upper floors.
See: Basement Air Sealing
Basement and crawlspace air leaks interact with air leaks in the attic and living space...
In winter, for each cubic feet of hot air leaking out through the upper parts of the house, another cubic feet of cold air will enter through gaps and openings at the bottom of the house; and the same happens in the summer, in the opposite direction.
Radiant floor heating is a much praised heating system, able to provide high levels of comfort in large homes with low levels of insulation.
But radiant floor heating is expensive and it doesn't make sense in energy-efficient buildings.
Electric radiant floor heating is expensive to run.
But what about just heating the floor? Many people like warm floors, to go around barefoot…
Concrete on-grade floors should be insulated, in cold and mixed climates. And the same goes for basement floors, or for crawlspace floors.
But what about wood-frame floors over basements and crawl spaces?
Perimeter and under-floor concrete slab insulation can reduce energy bills by 10%–20%, in cold and mixed climates. The investment should pay for itself in energy savings in some few years.
Unfortunately, many builders do not recognize the importance of concrete slab insulation, and homeowners are often misinformed over their importance.
Concrete and other masonry floors can act as thermal batteries, in passive solar strategies.
The idea is to use them to absorb solar heat gains during the hotter parts of the day (in the winter), and to release that heat during the evening and nighttime, as temperatures fall.
Our Video On Floors