How Much Money Is Saved by Superinsulating an Attic?

Determining Insulation Needs

• Superinsulating an attic is one of the easiest home projects that will reduce energy leakage. Energy costs will continue to rise, and a well-insulated attic will help defer much of those costs. Most U.S. building codes require insulation ratings between R-22 and R-49 (depending on climate). However, most homeowners' current insulation is between 25 and 50 percent less than what their current energy code requires.

  Measure the current thickness of insulation in your attic. Less than an R-22 (7 inches) is a good indication that more insulation is needed (in most U.S. climates). The USDOE has a zip-code insulation program that will calculate the most economical insulation level and outline the rate of return on your investment.

To Add or Replace Insulation

• When adding insulation to an attic there are two main choices: adding more to existing insulation or replacing existing insulation. Taking out old insulation is more costly; however, depending on the age of both the home and the insulation; it may be worth it. Older homes may have vermiculite insulation that can contain asbestos. If you're unsure, contact an insulation contractor to assist in installation. Eradication of asbestos is worth the extra cost in hiring an insulation contractor.

Types of Insulation

• Some types of insulation are do it yourself, while others require a professional. Homeowners typically install blanket or blown-in insulation. Blanket insulation is flexible and made up of fiberglass or rock wool. Batting is cut to fit an area. Blown-in insulation is often used in unfinished attic spaces. Homeowners can rent the blower at their home improvement store. Insulation types typically reserved for professional installation (and therefore more expensive) include foam, rigid and reflective insulation systems.

Radiant Barriers

• Radiant barriers are most effective in regions with hot climates. The barriers are made up of reflective material that can reflect heat in lieu of absorbing it. For maximum effectiveness and to reduce fire hazards, professionals should install radiant barriers. Radiant barrier performance is determined by emissivity, reflectivity and the angle of radiation. There is existing controversy on whether radiant barriers are worth the additional cost.