Q: We are planning our "dream" house. We want it to be
stylish, but also energy efficient and reasonably priced. With
concerns about terrorism, its strength and airtightness are
important. What do you suggest? - Jon M.
A: One of the best house construction methods, considering
your particular concerns about disasters, is stay-in-place-form
concrete walls. These houses are not only super energy efficient,
but they are extremely strong. Even tornado or hurricane winds won't
blow one down.
Other than deeper window openings, these homes look like any
other. Your architect will actually have more styling flexibility
due to the strength. Interior and exterior walls can be finished
with drywall, paneling, siding, brick or stucco.
I would recommend one of the foam block building methods. These
are large, often four-foot-long, hollow foam blocks. They are
usually made of polystyrene insulating foam like a cooler. Once the
blocks are stacked up to create the wall, concrete is pumped in the
top to fill the hollow block cavities.
You can expect your utility bills to be about half those of a
code stick-built house. This results from the high insulation level
and the efficiency benefits of the high thermal mass of the
concrete. The overall building cost is only about three to five
percent more than a lumber stick-built house.
The first thing you notice when you enter one of these houses is
how quiet it is. The heavy insulation and concrete mass inside the
walls block outdoor noise. With the concrete core and tight sealing
foam blocks, the homes are very airtight. This is an advantage for
your terrorism concerns.
You have several choices of foam block designs. One type, called
waffle, uses molded all-foam blocks with internal webs. This creates
continuous cavities of various widths. If you would break away the
foam insulation after the concrete sets, the concrete surface would
resemble a waffle.
Another effective design is a flat wall. These blocks are made of
flat sheets of foam insulation, usually about two inches thick.
There are metal or plastic webs in between them to space them apart.
When the concrete is poured in, it forms a core of constant
thickness, often six to 12 inches.
The waffle-type blocks produce a higher overall insulation level
because there is more foam. Also, less concrete volume is needed to
fill the wall. Talk to builders to see which they prefer to use in
your area. A third foam block design produces a post-and-beam
concrete pattern inside the blocks.
There are also new foam floor/ceiling/roof insulating foam forms.
Concrete is poured over them and in channels. They are very strong,
efficient and quiet.
