Recommended Insulation Levels for Energy Efficient Homes

Recommended Insulation Levels for Energy Efficient Homes

recommended insulation Levels FOR CEILING, WALLS, FLOORS AND BASEMENTS in different climates

Consider very high levels of insulation all over the boundary of your home, above the minimum requirements of building codes. That’s critical for home energy improvements.

Common wall insulation levels fall short of the best. Energy experts recommend much higher levels for attics, walls, floors and basements.

Climate and recommended insulation levels

Insulation requirements vary with climate. In very mild climates, with very low heating and cooling bills, you may not need the high levels of insulation shown in the table. And in some hot climates, the values shown above, may not be the right ones.

There are some few cases, involving tropical climates, where cooling is mainly achieved with the use of shade, breezes and natural ventilation, and where insulation is used very selectively (in air-conditioned rooms), or where reflective insulation (namely at the roof level) is more important than bulk thermal insulation.

But the general rule, in most climates, wherever heating and cooling bills are high, is rather different. Massive thermal insulation is crucial, and you should install the maximum amount of insulation possible in your walls, ceilings and floors.

Recommended Attic and Ceiling insulation levels

Installing attic insulation is typically inexpensive and easy. And it is crucial both in cold and hot climates. See: Attic Insulation for energy improvements.

Hence the high R-values recommended by energy experts for attics and ceilings, in all climates: US R-50 or even R-60 (Metric System: U-1) .

Recommended Wall Insulation levels

In hot and moderate climates, wall insulation is not as critical as attic insulation. The difference of temperatures between the two sides of the exterior walls doesn’t reach the levels of the attic, and since it is this difference that drives the heat flow, wall insulation doesn’t need to be so high.

But that doesn’t meant that it isn’t important. In cold climates, wall insulation is at least as important as attic insulation.

Hence, the recommendation of US R-values of 30-40 for cold climates and about R-20 for other climates.

The problem with these high levels of wall insulation is that they aren’t easy to achieve in some types of home construction. The depth of wall cavities may not provide enough space for high insulation levels

To overcome this problem you may:

1) use insulation products with high R-values

2) use a continuous sheet of insulation over the wall (insulated sheathing);

Recommended Insulation Levels for Energy Efficient Homes

3) use, in the case of wood frame construction,

i) two-by-six walls (instead of two-by-four),

ii) 24 inches space walls (instead of 16 inches) or

iii) new advanced wood framing techniques. (see: Wood Frame Walls).

Recommended Floor and Foundation Insulation Levels

The issue of floor insulation and foundation wall insulation should also be conveniently addressed. Heat also flows through floors, namely those over crawl spaces and basements.

In some hot climates, floor insulation may not be an important issue, but in most other climates it’s crucial. The recommended R-values in cold climates very high, as shown in the table I above.

See. for details:

R-values and installation


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