It depends on where you live and what comfort level you are looking for. In Maryland and Virginia, the recommended minimum R-value is R38 for attics. To learn more, check out the Department of Energy’s guide to insulation: Guide To Insulation
No, unless a mold or pest infestation issue if found. A big benefit of blown-in insulation is that it can be blown on top of existing insulation in your home, saving you money by utilizing what is already there. The only reason we would recommend removing existing insulation is if it has been contaminated by mold or feces from mice, bats, or other wildlife.
Energy savings through lower heating and A/C bills. Homes in the Mid-Atlantic can save up to 17% on energy costs with proper insulation according to the U.S. Department of Energy. Poorly insulated attics will allow hot air from attics in the summer to warm your home which makes your A/C run more. Conversely, in the winter, heat will escape from your home up through the attic making your heating system run more. Properly insulated attics are one of the best ways to make your home more energy efficient and save money on your utility bills.
There is a cost to remove existing insulation and to install new. Every job is different. However, the cost to install R-38 (minimum requirement in the mid-Atlantic) blown-in insulation ranges between $2.50- $3.50 per square foot. Removal of any existing insulation would be extra. Blown-in insulation is the least expensive option for re-insulating older attics especially if there is already existing insulation that can be utilized.
We have facilities in Virginia and Maryland and service the entire metro DC area. Please click here to see our service area by specific county, city and town.