[Greenbuilding] first certified Passive House in Canada

[Ross Elliott]

Doh! I KNEW I was missing a mandatory! So there's four, not three. 

 

John, maybe I've been brainwashed by the Germans, but I kinda like that 0.6
ACH50. According to the good Dr. Feist at that level of air tightness you
won't get any hidden condensation problems (don't ask me why, I just believe
everything I hear). My own place meets R-2000's 1.5 ACH50, yet in the last
cold snap I discovered several frost balls on the outside of the foamboard
(which would soon be hidden behind siding) where I've got some small air
leaks. We've got a tract builder here in Ottawa who has built hundreds of
homes in a row below 1.5 ACH50, so I don't think it's unreasonable to shoot
for better on a custom green home.

 

The "sophisticated computer program" we've been using for R-2000 since 1983
actually doesn't work that well for high performance houses beyond the
current R-2000 / ERS 80, there's going to be real problems getting them to
NRCan's magical ERS 86 or 87 in the next version of R-2000 without using
heat pumps everywhere. HOT2K just isn't that good at modeling great
envelopes right now. It's also a "black box" where we just have to accept
the results are accurately calculated, whereas the PHPP Excel spreadsheet
allows you to see what's going on - not that it does a guy like me any good
to know the formulas, but at least it's there for smarter people than me to
quibble over.

 

The Net Zero homes use exorbitantly expensive renewable energy systems to
push them to zero, whereas in my humble opinion if they're not up around
Passive House for their building envelope before they go for renewable then
they're just buying energy to waste, at a lot higher cost than from the grid
or pipeline. Talk about a science experiment. And if your total annual
energy bill is under $1000 because you built a true energy efficient home,
then putting $25,000 worth of PV on the roof seems like just a political
statement, since those PV panels will be obsolete long before they pay for
themselves (notwithstanding taxpayers covering the cost through incentive
programs). But I really do appreciate your insights into where the tradeoffs
should be in terms of cost, energy savings and carbon emissions, it's a
conversation well worth continuing. Passive House may not be the answer to
everything, but I think it's better than any of the alternatives currently
available.

 

But John, I really do have to agree with you about one thing. Mike Holmes is
definitely not someone you want promoting anything to professional builders
or renovators!  

 

Ross

 

From: jfstraube [mailto:jfstraube at gmail.com] 
Sent: Tuesday, January 25, 2011 4:25 PM
To: relliott at homesol.ca; Green Building
Subject: Re: [Greenbuilding] first certified Passive House in Canada

 

I think it is clear that you can build a PassivHaus standard home anywere.
The question is, should you?  More nuanced, the question is, "is the PH
standard the optimal home for the location and purpose envisaged".

CMHC has supported the construction of a whole bunch of Net Zero Energy
houses across Canada, a  more stringent energy standard than PH. This does
not mean it is a good idea.  However, the design teams are, under the target
of Net Zero, allowed to trade off the cost of insulation, the cost of
airtightness, and the cost of generation for their specific building and the
climate in which it is built.  PH is more dogmatic.

 

I really like PHPP, but it is an Excel spreadsheet, not magic.  R2000 home
builders have been required to use a more sophisticated computer program and
blower door test to verify their energy use compliance since forever (OK, 20
years).  They just have not set sufficiently low targets.  I strongly agree
that if PH can convince people to use a model to predict energy use and do a
blower door test to confirm airtightness, then it will be a huge benefit.
But one does not need to follow some of the dogmatic rules, like 0.6 at 50, to
get a durable, healthy, afforable, and low energy building.  There are
numerous other tried and true methods. PH is just one set of numbers that
one group chose. 

 

PS  The PH standard DEFINITELY has a requirement of 0.6 ACH at 50 Pa.  The 10%
overheating is rarely listed. 

See for example Wikipeadia

http://en.wikipedia.org/wiki/Passive_house#Requirements

and

Passive House USA

http://www.passivehouse.us/passiveHouse/PassiveHouseInfo.html

 

 

PSS If Mike Holmes is behind it, then PH just dropped in my estimation. Pop
culture, yes, science and fact, NOT!

 

 

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