Cutting Your Energy Bills
Your home consists of two primary systems that work together to provide
comfort and shelter. Your home's heating and cooling system maintains
comfortable indoor temperatures. Your home's envelope helps hold in comfortable
indoor temperatures and provides shelter from exterior elements. The home
envelope is the combination of materials that surround the interior space you
live in including walls, floors, ceiling, roof, windows, and doors. The quality
and integrity of your home's envelope greatly affects the comfort and cost to
operate your home.
- How can improving my home's envelope save money and energy?
- What are the benefits of an energy efficient envelope?
- Why is insulation important?
- What are air and vapor barriers?
- Why is air sealing important?
- What should I know about ventilation?
- Should I install the insulation myself or hire a contractor?
- Why should I hire a professional?
- What should I know if I'm going to hire a contractor?
Gas prices at a glance.
How can improving my home's envelope save money and energy?
The average family spends $1,900 a year on energy bills, nearly half of which
goes to heating and cooling. These costs can be reduced by up to 20% by
combining the right amount and type of insulation, using effective air sealing
techniques, and installing windows that are appropriate for your climate.
What are the benefits of an energy efficient envelope?
- Reduced drafts and even room temperatures (no cold or hot rooms).
- Reduced noise transmission into your home.
- Savings on heating and cooling bills.
- Moisture control in your home leading to longer life of your home's
building materials and reduced incidence of mold and mildew.
Why is insulation important?
The proper type and level of insulation for your home provides a continuous
thermal barrier minimizing heat flow through the walls, ceiling, and floor. The
result is a more comfortable home and reduced heating and cooling costs.
Installing insulation properly is as important as the type and level of
insulation because gaps, voids, compressions, and moisture reduce the
effectiveness of insulation and allow unconditioned air to enter your home.
What are air and vapor barriers?
Air barriers are any material used to prevent the movement of air through walls,
ceilings, and floors. Vapor barriers keep moisture, which is often contained in
air, from passing through and condensing in walls, floors, and ceilings. Air and
vapor barriers must be installed in a manner appropriate to your climate region
to work correctly. This is always toward the warmer side of the wall or ceiling.
Remember: Check your local code to see what is appropriate for your climate
Why is air sealing important?
Ceiling, wall, and floor systems with insulation generally provide barriers to
outside air coming into the home. However, small gaps, cracks, and spaces that
are not closed around penetrations will allow uncontrolled outside air from
entering temperature-controlled spaces. You will feel air infiltration from
larger gaps as drafts that make a room uncomfortable. To detect smaller cracks
that affect the energy efficiency of your home, you may need to hire a
professional contractor who uses a blower door and other tools to determine the
location of air leakage.
Remember: It is always a good idea to check your hot water heater, furnace,
gas stove and other combustion appliances as well as your carbon monoxide
detectors to make sure they are in working order.
What should I know about ventilation?
Although air sealing is intended to prevent outside air from leaking into your
house, a certain amount of controlled fresh air is important to keep the indoor
air quality healthy. Proper ventilation provides fresh air and removes stuffy
indoor air and excess moisture. Once your home is properly air sealed you should
make sure that adequate ventilation is provided. To do this, you may need to
hire a professional to conduct a blower door test. Ventilation to remove excess
moisture and pollutants can be as simple as exhaust fans in the kitchen and
bathrooms. More complex systems can cover the entire house and may include heat
recovery, moisture control, and air filtering.
Remember: Everyday activities such as cooking and bathing create moisture
that needs to be expelled from the house to avoid mold and mildew. This will
also help to keep the insulation dry so that it provides an effective thermal
barrier from outside conditions.
Should I install the insulation myself or hire a contractor?
There are air sealing and insulation activities you can do yourself. A careful
homeowner can often insulate attic floors, basements, new or open walls, and
crawl space walls. Blown-in and sprayed-in insulation as well as adding
insulation to a mobile home are best left to the professional installer. It's
important to remember, however, that insulation needs proper air-sealing to work
well. And without the necessary training and equipment, you won't know what your
air-leakage is, nor if you have combustion safety problems.
If you do choose to tackle this effort yourself, the Energy Star Home Sealing
Guide offers specific recommendations on ways you can tighten your home
envelope. You can learn more on the
Energy Star Web site.
Why should I hire a professional?
Energy consultants use tools such as blower-doors to diagnose your house and
develop a plan for the most cost-effective measures to take in your particular
What should I know if I'm going to hire a contractor? Shop around and
get several written bids for the same work (same R-value), and remember that
good quality is as important as low cost. Get a receipt. The contractor is
required by the Federal Trade Commission to provide you with a signed receipt
that shows the R-value. Consider having the installation checked by a
third-party, energy consultant or home inspector to make sure it has been
Source: U.S. DOE/EPA Energy Star Program