Page 25 - CodeWatcher Summer 2017

to rely on energy modeling software to guide you to the right
solutions. Currently, that’s not something designers can con- “Going forward, the
fidently do using the HERS/ERI path,” said Schwarz.
■ Mass Walls. The HERS/ERI does not model thermal industry may need to
■
mass effectively, especially when combined with insulation,
like we see with most insulated concrete wall systems. While make a decision to
it relates to the previous bullet, it can also be problematic for
custom home builders who are simply using these high-per- either only use the
forming wall systems to more easily provide their clients
with code compliant homes. HERS/ERI path as it
■ Ventilation. Building tight and ventilating right is a basic
■
building science principle. The difference between supply,
exhaust, and balanced ventilation is not adequately account- was intended (to
ed for in the current modeling software.

Pick and Choose? create an index score)
We appear to be at a crossroads: We want a system that not or to significantly
only quantifies the efficiency of a home but also develops
a true energy model that can answer complex questions enhance the system to
about the performance of the entire home as well as the
components that built it. The HERS/ERI path is not that be able to adequately
system.
Going forward, the industry may need to make a decision
to either only use the HERS/ERI path as it was intended (to answer other in-depth
create an index score) or to significantly enhance the system
to be able to adequately answer other in-depth performance performance questions
questions we have about our homes.
There will always be ways to improve modeling programs, we have about
and we should always strive for ways to improve them. The
day we stop offering suggestions is the day people stop our homes.”
caring, and that is far worse for our industry. CW
Robby Schwarz
Mike Collignon in Executive Director of the Green Builder Coalition.

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