Energy 05

Energy 05

As we continue our conversation about how your new home will protect you from the howling winds and bitter cold today let's take a look at the basement and how it can and does affect the Energy Efficiency of your home.  Every home built in Vermont is now required to insulate the basement so that it meets The Vermont Energy Code!

There are TWO basic theories of insulating a foundation:

  1. Insulate the INSIDE of the foundation - this is where one of many types of insulation are put near or against the concrete foundation on the inside.
  2. Insulate the OUTSIDE of the foundation - this is where insulation, typically rigid foam is placed against the outside of the foundation wall.

The two ways to insulate a basement are hotly contested and frequently discussed.  We at Vermont Modular feel as though everyone has earned the privilege of being wrong.  So, we will let you know what we think is the right way to insulate the foundation.  Put the insulation regardless of what type you choose to use on the INSIDE of the concrete wall.  If you insulate on the inside you will not be using energy to heat the Thermal Mass of Concrete; your energy will be used to keep the air in the basement warm.

Insulating the outside of a foundation we think is foolish, it leaves the foam exposed to the elements even if a protective coating is applied.  Expending energy to heat the huge mass of concrete makes no sense to us, use energy only to keep the basement warm.  Probably the worst way to insulate on the outside is when the foam stops at ground level leaving the top 18" or so of the concrete exposed to the bitter cold.  We think this is similar to leaving the window open but only half way.

Insulating on the INSIDE of the foundation wall can be accomplished using many different techniques:

  • Spray foam - using closed cell spray foam against the foundation is probably the best way to insulate as it completely seals everything and stops cold air penetration
  • Rigid foam boards - the use of rigid foam boards is excellent yet it needs to be sealed at the top near the sill plate to eliminate cold air penetration
  • Fiberglass Batt insulation - batt insulation is widely used as it is inexpensive and can be done by the homeowner.

During the summer heat the concrete which will remain chilly because of the earth's constant 52 degree temperature.  The chilly concrete will sweat in the summer heat exactly the way a cold can of soda sweats.  The inside of the concrete needs to be covered keeping it away from the hot humid air that is typical of July and August.

Call us, we can help!

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