How Valuable is a Well Insulated Home?

The best way to make your home more energy efficient and save money on your home energy bills is to increse it’s insulation. Targeting your home’s exterior—walls, windows, doors, floors and attic is the starting point for the most effective strategy for improving household energy efficiency. The better insulated and air tight your home is…the more effective each unit of heat is in creating a comfortable living environment for your family. [See this detailed diagram on Where to Insulate in a Home from the US Dept. of Energy]

In fact, passive homes are those that are so well insulated and air tight that all they need is the sun, body heat (humans:), appliances and a little heat recovery…no furnace necessary! So it’s very possible to have the insulation aspect of a house so well handled that worrying about heating bills becomes a thing of the past.

When you’re considering heat loss, homes can be grouped into 3 types:

  • Leaky homes – have solid walls, poor loft insulation, uninsulated floors, single glazed windows and lots of drafts. Because of all this…it needs 300 kilowatt-hours of heating for each square meter of space per year (kWh/m2a) just to stay warm.
  • Modern homes – have insulation in wall cavities and lofts, insulated floors, double glazing and some draft excluders. Because it has better insulation…it only needs half the heating of the leaky house, 150 kWh/m2a, to maintain a similar internal temperature.
  • Passive homes – have excellent materials in all insulation types, triple glazed windows that face the equator to maximize solar gains, and is so air tight it uses a ventilation system to keep the air fresh. It needs just 15 kWh/m2a of heating, some of which comes from heat recovery in the ventilation system.

What’s the bottom line in annual heating costs?  The leaky home’s heating bill might be $1,500 a year, $750 for the modern and $100 for the passive house.

How can you put this information to good use for your own Home?  Unfortunately, investing in good insulation makes most sense when building a new home or doing a major remodel.  Retrofits require real talent if they’re going to be cost effective.  Nevertheless,  if you’re a home owner…many types of insulation are a worthy investment. The colder your climate and the higher your fuel costs the better the paybacks are…and the more it makes sense.

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