Insulation Upgrade Cost Saving Calculator

Use this calculator to estimate the cost saving and greenhouse gas reduction for upgrading your insulation or windows.


You may be surprised how quickly more insulation will pay for itself.


Examples and Hints here...


Please read this!

A caution: This calculator is likely to overestimate the savings you will get for adding insulation.  The reason is that it does not take into account that part of the heat for your house is provided by warm bodies, electrical appliances and lights that generate heat, and solar gains through windows (if any).  The amount of the overestimation depends on your climate, your house, how you live, how efficient your appliances are, etc.  Climate is the biggest factor  -- for cold climates the, the amount of the overestimation will likely be small, and can probably be ignored.  For warmer climates (say 3000 deg-days and less), the error can be considerable, but in these cases, you will probably also have cooling costs that the insulation will help reduce.

So, like most engineering tools, its a useful guide, but not infallible. 


Enter Values Below
Area to be upgraded Square Feet Enter the surface area of the space where insulation is to be upgraded.
Heating Degree Days HDD (Fahrenheit) Help on finding Heating Degree Days for your area
Current R Value US R Value Help on looking up R values
New Total R Value US R Value Help on looking up R values
Pick your fuel type below -- Then, correct fuel cost and furnace efficiency if desired
Natural Gas
Fuel Oil
Click Calculate button to update fuel saving
$ Saving per year Dollars The dollar saving in fuel cost for the first year.
$ Saving for 10 years Dollars The dollar saving in fuel costs for the first 10 years, assuming a10% increase in fuel cost each year.
Greenhouse Gas Reduction lbs per year If electricity is the fuel, it is assumed it is generated in a coal fired power plant.



It should be noted that insulation also saves money on cooling bills, and these savings are NOT calculated by this calculator.  If you live in a hot climate this may be more important than the heating fuel saving -- maybe in the next revision.

If you are starting with an unInsulated wall, ceiling or floor, it is important to make a good estimate of the current R value.   See this R value help page.


Greenhouse gas emissions are high for electricity because the electricity is assumed to be generated in a coal fired power plant.  Coal plants are only about 30% efficient, and coal is a very high Carbon fuel.  About 50% of the power generated in the US is from coal fired power plants -- these coal plants account for about 80% of all US electric power generation CO2 emissions.


If you have any problems or comments on the calculator, please let me know -- Gary




Rev 3/24/06