For Homeowners
Insulation & Air Sealing
As certified home energy assessors, EnergyWize is trained to evaluate the efficiency and durability of a home.
We evaluate the patterns of energy usage and employ techniques such as a blower door test and thermal (infrared) camera imaging to locate the sources of air leaks.
We then determine the best course of action for sealing those leaks, such as installing insulation and air sealing.
Benefits of Insulation
Insulation material, when properly used, can make your home more comfortable and energy-efficient, greatly reducing heating and cooling bills throughout the year.
On average, you can save up to 15% on your home’s heating and cooling costs or up to 11% on its total energy costs by adding insulation to attics, floors, crawl spaces, and accessible basement rim joists that connect to the foundation, and by reducing unwanted air leaks all around your house.
Insulation is important because of its ability to reduce the amount of heat that flows between the inside and outside of your home. The ability of insulation material to reduce heat flow is called its R-value. The greater the R-value, the more this heat flow is reduced.
Where to Insulate Your Home
For optimal energy efficiency, your home should be properly insulated from the roof down to its foundation.
This illustration shows all the areas of the home where there should be insulation.
1. In unfinished attic spaces, insulate between and over the floor joists to seal off the living spaces below. If the air distribution is in the attic space, then consider insulating the rafters to move the distribution into the conditioned space. (1A). Insulate the attic access door.
2. In finished attic rooms with or without dormers, insulate (2A) between the studs of "knee" walls, (2B) between the studs and rafters of the exterior walls and the roof, (2C) and ceilings with unconditioned spaces above. (2D) Extend insulation into joist space to reduce air flows.
3. Insulate all exterior walls, including (3A) walls between living spaces and unheated garages, shed roofs, or storage areas; (3B) foundation walls above ground level; (3C) foundation walls in heated basements.
4. Apply insulation to floors above unconditioned spaces, such as vented crawl spaces and unheated garages. Also insulate (4A) any portion of the floor in a room that is cantilevered beyond the exterior wall below; (4B) slab floors built directly on the ground; (4C) as an alternative to floor insulation, foundation walls of unvented crawl spaces. (4D) Extend insulation into joist space to reduce air flows.
5. Do not forget to insulate the band joists.
6. Caulk and seal around all windows and doors.
Learn more about home insulation at the Energy.gov website
Air Sealing Your Home
Air sealing is one of the most cost-effective ways to improve the comfort and energy efficiency of your home.
Proper insulation helps keep a house warm in summer and cool in winter. Insulation works by blocking the flow of heat through a surface such as a wall or roof. But insulation does not necessarily block the movement of air, especially when cracks, holes, or other gaps are found in the house. Think of insulation as a sweater — it can keep you warm when the air outside is cold, but it doesn’t block the wind. For that you need a windbreaker. Air sealing acts like a windbreaker. Air leaks can make your home feel drafty and uncomfortable and place an unnecessary strain on heating and cooling equipment, which decreases their efficiency and raises your energy bills. Air leaks can also let in moisture that can warp and damage wood and lead to mold.
Air Leak Locations
Air leaks can occur anywhere gaps exist in the home. Those around windows and doors are the most obvious, but there are often many smaller and less detectable gaps present. Air leaks can also be found where rising warm air is replaced by cooler air (as often happens between an attic and the conditioned spaces below) or where exposed insulation contains dirty spots (showing air infiltration). Air leaks also often occur where brick and wood siding or foundations and walls meet. At least 19 key areas (shown in the illustration) have been identified where air sealing can improve a home’s energy efficiency, comfort, and building durability.
