Insulation Calculator

Insulation Calculator

From Kurt P.

Is there some simple way to determine how much insulation a house should have?

Thank you



Hi Kurt,

How much insulation is enough insulation? Well, each state has minimum insulation levels for each component of a house, such as walls and ceiling and floor, usually spelled out in local building codes.

It is important that your house at least meet these minimum standards, and if possible exceed them.

The cost of increasing or exceeding minimum insulation standards is not high and the payback is rapid.

Not only do you save money on heating and cooling but you help save the environment.

Here is an installation calculator that is easy to use whether you are building a new house or trying to determine if your present home has enough insulation. It’s the best I’ve seen to determine R-values. An R-Value indicates insulating power or thermal resistance. The higher the R-value, the greater the insulating power. Higher R-values are more effective at maximizing your energy savings and comfort.

Click on picture for calculator:

http://www.jm.com/insulation/technical_info/3001.htm

And here's an R-value chart from the U.S. Department of Energy - Energy Efficiency and Renewable Energy


These recommendations are cost-effective levels of insulation based on the best available information on local fuel and materials costs and weather conditions. Consequently, the levels may differ from current local building codes. In addition, the apparent fragmentation of the recommendations is an artifact of these data and should not be considered absolute minimum requirements.

Click to enlarge:

A. R-18, R-22, and R-28 exterior wall systems can be achieved by either cavity insulation or cavity insulation with insulating sheathing.For 2 in. x 4 in. walls, use either 3½ in. thick R-15 or 3½ in. thick R-13 fiber glass insulation with insulating sheathing.For 2 in. x 6 in. walls, use either 5½ in. thick R-21 or 6¼ in. thick R-19 fiber glass insulation.

B. Insulate crawl space walls only if the crawl space is dry all year, the floor above is not insulated, and all ventilation to the crawl space is blocked.A vapor retarder (e.g., 4- or 6-mil polyethylene film) should be installed on the ground to reduce moisture migration into the crawl space.

C. No slab edge insulation is recommended.

For additional information, contact your local utility, and a professional insulation contractor.

Carl