[Greenbuilding] Aggressively Passive: Building Homes to the Passive House Standard

[Alan Abrams]

<A higher standard than the PH one is a NetZero energy house.>

yadda yadda.  what I see out there (as greenbuilding laity--not as an
engineer) is convergence. Last fall, I had the opportunity to study the
plans for the Net Zero Energy test house, designed by Building Science
Corp--and--Lo!--it was in essence a passive house.

Or vice versa--one could say that PH--which focuses on envelope design and
internal systems--is the optimal platform for adding renewable systems to
achieve net zero or positive performance.

Anyway, speaking of the NZ test house--it shares with PH the same
principles--air tightness, super insulation (by code standards), fresh air
ventilation system, dynamite windows, and a killer job with mitigating
thermal bridging.  Where it beats the shorts off of Passive House (based on
their manual of standard details) is that it is carpenter friendly, using
substantially conventional framing, with some complex but straightforward
and consistent rain screen, air barrier, and exo-insulation details.  I did
not get my hands on any of the energy modeling for this project, but I
assume it was done on a platform that is analogous to PHPP.

The greater commonality, however, is this: looking at energy design from an
integrated, systematic, performance based POV, rather than a prescriptive
approach.  To me, with 35 years in the trenches, this was the most important
thing I took away from Passive House training.

With regard to the deficiencies of Passive House for the US--please consider
that PHIUS is a shoestring operation, basically created out of little more
than the ceaseless and heroic energy of Katrin and Mike, and a few dedicated
staffers.  If they had the money and the muscle of DOE behind them, they
could resolve the discrepancies in ERV and window ratings, and so on. They
could also tweak PH to account for the wide range of climates in the US,
particularly in managing latent heat loads.  Instead, their limited time and
resources are devoted to training and certifying projects.

nevertheless, I am skeptical of all orthodoxy.  I like PH for a lot of
personal reasons as well as professional, but if NZ can prevail, and really
have a broad impact on design, amen.

AA

*Alan Abrams**
Abrams Design Build LLC*
*A sustainable approach to beautiful space*
alan at abramsdesignbuild.com
www.abramsdesignbuild.com
*202-726-5894 o
202-437-8583 c
202-291-0626 f*
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