first thing to understand about ‘zero-energy homes,’" says
Steve Homa of Muskego-based PEA Builders Inc., "is that no home by
itself can really ever be zero energy. Whether it be (in) Wisconsin or
Arizona, at some point in time it will be too hot or too cold to sustain
a comfortable temperature. That is when some external source of energy
will be needed — be it a wood stove, swamp cooler or some other fossil
The ultimate goal,
he continues, is to reduce the energy load on the house as much as
possible. And how exactly is that variable measured? The Home Energy
Rating System (HERS) index. "It is a national standard set up to
test or calculate a home’s energy performance on a scaled system —
zero being net zero, and 100 being a standard energy home," Homa
explains, adding that PEA has achieved HERS ratings of 35.
have made the home as efficient as possible, then the road to net zero
(or energy producing) is merely a matter of how much solar or other
sustainable energy you can add on," he says. Even then, Homa says,
the subsequent technicalities are tricky. "The only real way to
achieve net zero is to be grid tied with the local utility so that they
can buy back your excess energy production," he explains. "If
you build a home that can achieve all these goals but is off grid, then
at some point in time (at least in Wisconsin) you have to account for
days of zero production. A backup generator would then be needed, which
technically means you are no longer net zero."
challenges building a zero-energy home presents, its benefits extend
beyond the obvious feel-good factor. Homa says cost savings can range
from 5 to 20 percent, depending on what systems are used and how close
to net zero a customer wants to achieve — a substantial number
speaking, attractive design, free from clutter or exterior eyesores, is
entirely possible. "Many technologies, such as geothermal, are not
very visible," says Dave Belman, president of Belman Homes in
Waukesha and president of the Metropolitan Builders Association.
"Geothermal systems would be built underground, and the furnace is
only slightly larger than a conventional furnace. Solar panels are still
very visible, but if installed on the back of a home would not
drastically affect the outward appearance of the home."
So is it possible
to build a zero-net-energy home in Milwaukee? According to Homa, the
answer is yes. "It’s possible to achieve a zero-energy home just
about anywhere as long as you have the right components," he says.
"As a designer of ‘passive solar’ homes in Wisconsin, PEA
Builders certainly has the challenge of extreme highs and lows to deal
with, but this simply adds to the character and beauty of the
How is energy
produced in a high-performance home?
high-performance home, energy is usually produced by PV (solar panels)
or wind," explains Homa."This energy can be used directly,
stored in batteries for later use, or sold to the power company."
or not, Wisconsin is a good location for solar usage and ranks in the
top 20 states, mainly due to incentive programs that are
available," Belman adds.
What does building
a low-net-energy home require?
"To reach a
HERS 35 requires careful planning and attention to detail," says
Homa, whose company has achieved this rating. "High levels of
insulation are very important, but more important is having an airtight
home. We also use high solar-heat-gain windows and passive solar design
to further reduce our homes’ need for fossil fuels."
Are there any tax
breaks for zero-net-energy homes? If so, what are they?
federal tax breaks for solar power — 30 percent off the cost of the
system," Belman says. "Wisconsin also offers property tax
exemptions, so you don’t pay property tax on the cost of the
equipment. (Equipment is) also exempt from state sales tax."
How much more does
it cost to