By clicking the "I'm not sure, use default estimate" option, you will select our rule of thumb measurement. We have determined that a good default value would be R-15. This is based on our experience having insulated over 5,000 homes in the area. The R- value for your home's existing insulation is determined by the type of insulation and how much (in inches of thickness) you have. The insulation in your attic settles at different rates over time, determine the average depth. The R- values for each type of insulation we use to come up with the total R- value are as follows:

• Cellulose = 3.5 per inch

• Fiberglass = 2.8 per inch

• Rockwool = 3.2 per inch