[Greenbuilding] first certified Passive House in Canada

Shawna Henderson s_henderson at me.com
Wed Jan 26 08:31:43 CST 2011


Hey Ross and John,

Here in NS, we have several small production builders who consistently  
come in at <1 ACH at 50, Keith Sawlor hit 0.29 (I personally did that  
test, about 15 years ago!!). On all of our custom design jobs, 0.5ACH  
@ 50 is the target on our bid documents. While not all builders hit  
that, they are consistently coming in at less than 1 and some are bang  
on, because they have long-standing crews who can do the air sealing  
work. Ross, I'm with you on the NZE house $25,000 PV extravaganza,  
which might make sense where there is a decent FIT, like ON, but here  
in NS, where ComFIT comes into play April 1, there is still no real  
business case for it (ie, ROI sucks). We ensure that the design and  
planning allows for 3 to 7 kW PV on the roof and with conduit (not  
wiring) in place and wall space in the mechanical area for inverter  
and controls, roof mount and any extra bracing etc in place as  
homeowner dictates. When it's affordable/cost-effective, homeowner can  
have it installed.

I agree with John on the issues around the energy modelling, and that  
a set of dogmatic rules leads us right back to the one-size-fits-all  
approach, which leads us right back to the problem of large tract  
builders and 1,000s of spec homes in GTA every year that are not  
meeting the +20-year-old R2000 standard, but are building to a one- 
size-fits-all approach, just using a different set of dogmatic rules  
driven by a different set of requirements ($/sf vs W/sf).

Cheers from mighty chilly Halifax

Shawna

On 25-Jan-11, at 8:12 PM, Ross Elliott wrote:

> 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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