Does Your Home Need More Insulation?

Print out this sheet and follow the instructions to find out.

 To begin to answer this question, you must first find out how much insulation you already have and then determine how much more is needed. Many older homes have less insulation than homes built today. First, check the attic; then check walls and floors adjacent to an unheated space like a garage or basement. In these places, the structural frame elements (the ceiling joists or wall framing boards) are often exposed, making it easy to examine the insulation (if any) and to measure the depth or thickness of the insulation. It is best to be conservative when measuring the thickness of loose-fill insulation in an attic as the area around the attic access has most likely been disturbed and the insulation could be piled or fluffed.   It is more difficult to inspect finished exterior walls and this is best left to professionals. Next compare your findings with the recommended levels of insulation by following the steps below.

Evaluating the R-value of Insulation Previously Installed in Existing Homes

Your home may have one or more of several different insulation materials. Mineral fiber insulation, including fiber glass and rock wool, is produced from either molten glass, slag, or rock. Fiber glass insulation is usually very light-weight, and yellow, pink, or white in color. Fiber glass can be found in loose-fill and blanket, either batt or roll, forms. Rock wool loose-fill is usually more dense than fiber glass, and is most commonly gray with black specks. Some rock wool products, however, are near-white. Loose-fill cellulose insulation is commonly manufactured from recycled newsprint, cardboard, or other forms of waste paper. Most cellulose is in the form of small flat pieces rather than fibers. However, some cellulose products are so finely divided they look fibrous as well.

*Includes Effects of Aging and Settling

Use this formula to determine the R-value of your existing insulation:

 Determining the R-Value You Need for an Existing House

The amount of insulation you need depends on the climate, type of heating (gas, oil, electricity) you use, and the section of the house that you plan to insulate.

The following table shows the governmental recommendations for buildings with natural gas heating systems in our area of the country.

R-Value Recommendations for Existing Buildings

Heating System: Natural Gas Furnace
Cooling System: Electric Air Conditioning
First 3 digits of ZIP code: 605
Location: South_Chicago_Sub., IL

^* The recommendations are based on an analysis of cost effectiveness, using average local energy prices, regional average insulation costs, equipment efficiencies, climate factors, and energy savings for both the heating and cooling seasons.

The next step is to compare the R-value of your insulation with the recommended R-values for your house and your type of space heating.

Use this formula to determine how much insulation you need to add:

If the “R-value needed” is an R-8 or greater it is likely to be cost effective to install insulation to the area in question. If you would like someone from our office to come out to your home and provide you with an estimate for installing additional insulation just call us at (630) 420-1962.