| Building a concrete home with insulating concrete
forms (ICFs) saves energy and money. The greater insulation, tighter
construction, and temperature-smoothing mass of the walls conserve
heating and cooling energy much better than conventional wood-frame
walls. This reduces monthly fuel bills. It also allows use of smaller
heating and cooling equipment, saving money in construction.
How much will I save?
Houses
built with ICF exterior walls
require an estimated 44%
less energy to heat and 32% less
energy to cool than comparable
frame houses. A typical 2000
square foot home in the center
of the U.S. will save approximately
$200 in heating costs each year
and $65 in air conditioning each
year
The bigger the house the bigger
the savings. In colder areas
of the U.S. and Canada , heating
savings will be more and cooling
savings less. In hotter areas,
heating savings will be less
and cooling savings more.
The smaller heating and cooling
equipment needed for such an
energy-efficient house can cut
construction costs by an estimated
$500 to $2000. The biggest equipment
savings come with the houses
that have the most energy savings.
 Where do the savings come from?
I nsulating values for ICF walls
using polystyrene foam are R-17
to R-26, compared to wood frame's
R-9 to R-15. So ICF walls are
expected to cut the conduction
losses through foundation and
above-grade walls by about half.
And ICF walls are tighter. In
tests, ICF houses averaged about
1/2 as much infiltration (air
leakage) as frame.
But ICF walls do more than cut
down on the biggest types of energy
loss. The concrete gives them the
heat-absorbing property, “thermal
mass”. This is the ability
to smooth out large swings in temperature.
It keeps the walls of the house
a little warmer when the outdoor
temperature hits its coldest extreme,
and keeps the house a little cooler
when the outdoor temperature is
hottest. The walls themselves “add
back” heat or cooling to
the house when it needs them most.
This contributes about 6% of the
needed energy to the house for
free.
 Reduced equipment costs result
from the energy savings. Since
the energy needed is less, the
furnaces and compressors that
heat and cool can be smaller.
And the more the energy savings,
the greater the possible reduction
in equipment size—and the
equipment cost.
 What's the bottom line?
In planning a new house you
can estimate that building the
walls of concrete using ICFs
will save you hundreds of dollars
per year in energy costs. As
shown in the graphs, the savings
are greater the bigger the house.
Heating savings are highest in
cold climates, and cooling savings
highest in warm climates.
Source: Insulated Concrete Form
Association
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