U.S. Department of Energy - Energy
Efficiency and Renewable Energy
A Consumer's Guide to Energy
Efficiency and Renewable Energy
Do-It-Yourself Home Energy
You can easily conduct a home energy audit yourself. With a
simple but diligent walk-through, you can spot many problems in
any type of house. When auditing your home, keep a checklist of
areas you have inspected and problems you found. This list will
help you prioritize your energy efficiency upgrades.
Locating Air Leaks
First, make a list of obvious air leaks (drafts). The
potential energy savings from reducing drafts in a home may range
from 5% to 30% per year, and the home is generally much more
comfortable afterward. Check for indoor air leaks, such as gaps
along the baseboard or edge of the flooring and at junctures of
the walls and ceiling. Check to see if air can flow through these
- Electrical outlets
- Switch plates
- Window frames
- Weather stripping around doors
- Fireplace dampers
- Attic hatches
- Wall- or window-mounted air conditioners
Also look for gaps around pipes and wires, electrical
outlets, foundation seals, and mail slots. Check to see if the
caulking and weather stripping are applied properly, leaving no
gaps or cracks, and are in good condition.
Inspect windows and doors for air leaks. See if you can
rattle them, since movement means possible air leaks. If you can
see daylight around a door or window frame, then the door or
window leaks. You can usually seal these leaks by caulking or
weather stripping them. Check the storm windows to see if they
fit and are not broken. You may also wish to consider replacing
your old windows and doors with newer, high-performance ones. If
new factory-made doors or windows are too costly, you can install
low-cost plastic sheets over the windows.
If you are having difficulty locating leaks, you may want to
conduct a basic building pressurization test:
- First, close all exterior doors, windows, and fireplace
- Turn off all combustion appliances such as gas burning
furnaces and water heaters.
- Then turn on all exhaust fans (generally located in the
kitchen and bathrooms) or use a large window fan to suck the air
out of the rooms.
This test increases infiltration through cracks and leaks,
making them easier to detect. You can use incense sticks or your
damp hand to locate these leaks. If you use incense sticks,
moving air will cause the smoke to waver, and if you use your
damp hand, any drafts will feel cool to your hand.
On the outside of your house, inspect all areas where two
different building materials meet, including:
- All exterior corners
- Where siding and chimneys meet
- Areas where the foundation and the bottom of exterior brick
or siding meet
You should plug and caulk holes or penetrations for faucets,
pipes, electric outlets, and wiring. Look for cracks and holes in
the mortar, foundation, and siding, and seal them with the
appropriate material. Check the exterior caulking around doors
and windows, and see whether exterior storm doors and primary
doors seal tightly.
When sealing any home, you must always be aware of the
danger of indoor air pollution and combustion appliance
"backdrafts"."Backdrafting" is when the
various combustion appliances and exhaust fans in the home
compete for air. An exhaust fan may pull the combustion gases
back into the living space. This can obviously create a very
dangerous and unhealthy situation in the home.
In homes where a fuel is burned (i.e., natural gas, fuel
oil, propane, or wood) for heating, be certain the appliance has
an adequate air supply. Generally, one square inch of vent
opening is required for each 1,000 Btu of appliance input heat.
When in doubt, contact your local utility company, energy
professional, or ventilation contractor.
Heat loss through the ceiling and walls in your home could
be very large if the insulation levels are less than the
recommended minimum. When your house was built, the builder
likely installed the amount of insulation recommended at that
time. Given today's energy prices (and future prices that
will probably be higher), the level of insulation might be
inadequate, especially if you have an older home
If the attic hatch is located above a conditioned space,
check to see if it is at least as heavily insulated as the attic,
is weather stripped, and closes tightly. In the attic, determine
whether openings for items such as pipes, ductwork, and chimneys
are sealed. Seal any gaps with an expanding foam caulk or some
other permanent sealant
While you are inspecting the attic, check to see if there is
a vapor barrier under the attic insulation. The vapor barrier
might be tarpaper, Kraft paper attached to fiberglass batts, or a
plastic sheet. If there does not appear to be a vapor barrier,
you might consider painting the interior ceilings with vapor
barrier paint. This reduces the amount of water vapor that can
pass through the ceiling. Large amounts of moisture can reduce
the effectiveness of insulation and promote structural
Make sure that the attic vents are not blocked by
insulation. You also should seal any electrical boxes in the
ceiling with flexible caulk (from the living room side or attic
side) and cover the entire attic floor with at least the current
recommended amount of insulation.
Checking a wall's insulation level is more difficult.
Select an exterior wall and turn off the circuit breaker or
unscrew the fuse for any outlets in the wall. Be sure to test the
outlets to make certain that they are not "hot." Check
the outlet by plugging in a functioning lamp or portable radio.
Once you are sure your outlets are not getting any electricity,
remove the cover plate from one of the outlets and gently probe
into the wall with a thin, long stick or screwdriver. If you
encounter a slight resistance, you have some insulation there.
You could also make a small hole in a closet, behind a couch, or
in some other unobtrusive place to see what, if anything, the
wall cavity is filled with. Ideally, the wall cavity should be
totally filled with some form of insulation material.
Unfortunately, this method cannot tell you if the entire wall is
insulated, or if the insulation has settled. Only a thermographic
inspection can do this
If your basement is unheated, determine whether there is
insulation under the living area flooring. In most areas of the
country, an R-value of 25 is the recommended minimum level of
insulation. The insulation at the top of the foundation wall and
first floor perimeter should have an R-value of 19 or greater. If
the basement is heated, the foundation walls should be insulated
to at least R-19. Your water heater, hot water pipes, and furnace
ducts should all be insulated.
Inspect heating and cooling equipment annually, or as
recommended by the manufacturer. If you have a forced-air
furnace, check your filters and replace them as needed.
Generally, you should change them about once every month or two,
especially during periods of high usage. Have a professional
check and clean your equipment once a year
If the unit is more than 15 years old, you should consider
replacing your system with one of the newer, energy-efficient
units. A new unit would greatly reduce your energy consumption,
especially if the existing equipment is in poor condition. Check
your ductwork for dirt streaks, especially near seams. These
indicate air leaks, and they should be sealed with a duct mastic.
Insulate any ducts or pipes that travel through unheated spaces.
An insulation R-Value of 6 is the recommended minimum.
Energy for lighting accounts for about 10% of your electric
bill. Examine the wattage size of the light bulbs in your house.
You may have 100-watt (or larger) bulbs where 60 or 75 watts
would do. You should also consider compact fluorescent lamps for
areas where lights are on for hours at a time. Your electric
utility may offer rebates or other incentives for purchasing