Most homeowners understand the concept of insulating the home. It helps the heating and airconditioning system works better and more efficiently. It also keeps the indoor condition from the more extreme temperature swings of the outdoor environment. What is sometimes missing is the knowledge of how much insulation is enough and what type should be used.
Insulation level is measured in R-value. The higher the R-value, the more resistance there is for heat transfer. Current minimum standard for new homes calls for R30 and we recommend consideration for R38 if space is available for Bay Area customers. You can find out how much insulation you have by checking out the depth of the existing insulation. Every inch of blown in insulation equates to roughly R2.5-4 of insulation value. So for example a house that has 3 inches of insulation has a rough R value of 7.5 to 12. That means the house has about 1/3 of the insulation compared with today’s minimum standard.
More information about insulation can be found at this Department of Energy fact sheet
Next time we will talk about an important step that is missed from many insulation project - attic air gap sealing