Before you purchase a home — whether new construction or old — it's smart to ask for the previous years' utility bills and a blower-door test.
We all know the symptoms of
a house that's leaking air.
Drafty halls in the winter
lead to rooms that suffocate in
summer. Then there's the most
uncomfortable pain of all high
Talk to an energy efficiency expert
from your local electric utility, and
one of the first things he or she will
do is ask about insulation in your
house. What type do you have? Is it
in the attic, walls, and floors? How
about the basement or crawl space?
Chances are leaky homes aren't
properly insulated. But it takes more
than a roll of fiberglass to stop air invasions.
Sealing the Envelope = Zipping Your Coat
"A major factor in larger monthly
energy bills in both the summer and
winter is an uninsulated, unsealed
building envelope," remarks Wade
Rahn, Customer & Technical Service
Coordinator for Butler Public Power
District, based in David City, Neb.
"You can lower energy bills by just
identifying and stopping air
A "thermal building envelope"
separates you from outside elements.
It's like wearing a coat when it's cold:
If you zip up your coat, it's nice and
warm, but if it hangs open, you're left
freezing. By properly sealing the
building envelope and creating air
barriers, and then installing
insulation, you keep hot air out in
summer and cold air out in winter.
Sealing your home's thermal
envelope involves applying caulk and
foam to cracks and gaps and
correctly installing insulation. If the
insulation isn't put in well, it's not
doing its job. Typically, incorrectly
placed insulation leaves gaps
between walls and doors or windows,
or where the ceiling meets the walls.
If there's a gap in insulation, heat
It's All About Air Infiltration
Understanding air infiltration is only
half the battle. You have to find and
stop the invaders.
"There are many tools we make
available to our customers to identify
and correct these deficiencies" Rahn
If your local public power district
or electric cooperative offers home
energy audits, take advantage of
them. Your utility's energy advisor
will determine if your home needs a
blower-door test, one of the best ways
of finding out how much air goes in
and out of your residence every hour.
If a thermal imaging camera is
available, the auditor can pinpoint
exactly where your home loses air.
Typical culprits include the roof,
around doors and windows, recessed
can lights, attic hatches and pulldown
stairs, and unfinished
basements or crawl spaces.
Don't overlook the obvious — check
where ceilings and floors meet the
walls, too. Do you routinely have to
clean a cobwebby corner? That's a
good indication of air infiltration
because insects like fresh air.
"What you don't see could be
adding a large portion to your
monthly bill" Rahn warns.
Caulk, weather stripping, and
expanding spray foam should take
care of those problem areas listed
above. You can also make a box of
rigid foam board for the attic pulldown
But insulation won't do any good if
you don't have proper air barriers —
if your house jacket isn't zipped.
While loose-fill fiberglass or
fiberglass batts keep heat from
moving in or out of your house, they
do little to stop air flow. In fact, if
every single joint and crack is not
sealed with caulk or expanding foam,
your fiberglass batt insulation does
little more than catch dust.
"Discoloration around the edges of
your insulation is a sign that outside
air and dust is being blown through the insulation" Rahn reveals.
Cellulose, made from recycled
newspapers and blown in, provides
good attic insulation because it does
more to stop air flow. Foam
insulation, while the most expensive,
also boasts the highest R-value —
the effectiveness rating given to
insulation — and completely blocks
Your local energy professional can
help determine the best type of
insulation for your house and also
help you work out a payback period
on your investment. You can also
check EnergySavers.gov for more
information about insulation, and
use their ZIP code calculator to find
out how much insulation you need
for your location.
The bottom line: "If outside air is
getting into your conditioned space,
your bills will be higher and you
won't be comfortable," Rahn