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

John Daglish johndaglish at online.fr
Tue Nov 1 10:28:01 PDT 2011

Bonjour jfstraube,

The PassivOn project has been calibrated for some European climates.

But using the PHPP planning package (15 or so linked excel
spreadsheets) with your monthly climate data you can modulate the u
values, etc. which does a fair stab at it for a static /steady state
calculation provided
you take into account the minimum requirements eg 10W/m2 max heat/cool load,
asymetric radiant temperature différences less than 4C, etc.
The PHPP package is correlated against constructed project operational
data * and
the PHI Passiv Haus Institutes inhouse dynamic (hourly) calculation

* eg. Cephus project measured results

PS its even better if you use low embodied energy building materials
(such as renewable plant fibers such as straw,
regard the S House


John DAGLISH, Secretary
Bâtir Sain association


Tuesday, January 25, 2011, 2:57:23 AM, you wrote / vous ecrirez:

j> The PH institute has done some work on this for their climate zone and it is on their websites somewhere (in Europe) but I could not find the link.  The answer is an emphatic yes: if the house is
j> supposed to last 50 years or more, embodied energy of the materials is a small portion of the lifecycle.
j> Getting to PH in the Bay area should be relatively easy and not require a lot of insulation materials (the <120 and <15 kWh/m2 are quite reasonable to achieve) for your climate: only the 0.6 ACH
j> number is hard , and that is not really a matter of materials, it is a matter of a lot of labor and testing which can cost an awful lot.  The 0.6 ACH target makes little sense in your climate (eg
j> does not save much energy or other problems) unless it is really easy to achieve: current buildings are lucky to get under 5, so you can see the distance between current practise and PH
j> airtightness. 
j> BSC did a modest net zero energy house in Oakland. It needs about a 4 kW PV array to get to zero energy, eg not to 120 kWh/m2 of PH, but all the way to zero. hwww.zetacommunities.com  
j> Basically, a decent small house in Minnesota, transported to the Bay Area is easy to get to Net Zero.  The carbon payback of PV arrays is typically given as a few years, likely in the 2-3 range
j> for many systems. Many others have shown Net Zero in the Bay area with modest and rather affordable PV arrays and heat pumps to make things easy, and most of these would meet the energy targets of
j> the PH, just not the airtightness level or some of the recommendations for things like windows and such.

j> On 2011-01-24, at 7:19 PM, Kirsten Flynn wrote:

>> Hello All,
>> I have not been piping up lately, I am an interior designer, and am passionate about green building, but have little to add in these more technical building science discussions.
>> I have a question about PH that has been niggling at me for a long time.  I know I live in an unusually temperate climate, the San Francisco Bay Area.  But it seems to me there is a challenge to
>> applying PH in this area.  My concern is that the embodied energy in building materials and the ongoing energy in mechanical ventilation, would out weigh the benefits in energy saving of a passive
>> house in such a moderate climate.  Could anyone out there direct me to information on the applicability of this standard to different climate situations?  Of course a tight house is a benefit in
>> any climate, but was wondering if the carbon cost/benefit analysis had been done on the PH standard.
>> As a side note, I tried to find the HDD and CDD information for my region on the NWS web site, and could not figure out how to get a yearly figure.  For my own information does anyone know to
>> access heating and cooling days per year for a specific region.  Not something I need for my business, but I would be interested to know.
>> Kirsten
>> On Jan 10, 2011, at 6:28 PM, JOHN SALMEN wrote:
>>> Welcome to the list - great letter and thanks for the link to the PANW
>>> discussion - it was fun to read. 
>>> As for being ambassadors for a better built environment I think one of the
>>> challenges with the 'toolbox' and accompanying vocabulary is that they can
>>> become prescriptive of what that built environment will be and houses people
>>> accordingly without really corresponding to actual use, social needs, or
>>> simply adapting. Like you say "...everything looks like a nail..." 
>>> In medical terms this is called 'compliance' and is both a form of authority
>>> and management towards a desired medical outcome. Problems really only arise
>>> when the outcome does not match the need or diagnosis - or the prescribed
>>> need was part of the toolbox that did not match the patients actual needs.
>>> Compliance to a building code is similar in that it is recognition of
>>> certain community standards and a willingness to be part of our community.
>>> Codes change both in reaction to compliance and needs on the part of the
>>> community. Alternate 'codes' or methodologies (PA, NZE and predecessors) are
>>> part of that process of change but environmental and social planning are
>>> also a big part. As builders, designers, planners and community members we
>>> participate in all those aspects - so the tool box gets bigger if you are
>>> meeting the needs of the overall community.
>>> As an example the question of PV has been an interesting one for me as net
>>> metering and solar roofs have been discussed for a long long time and I
>>> participated in discussions on this with BC hydro 15 years ago. If a typical
>>> residential roof can generate 1/3rd more energy than the house consumes it
>>> seemed a 'no brainer' to utilize the footprint and grid connection of a
>>> residential roof. 
>>> It was an appealing scenario but the main question then and now is 'who owns
>>> the roof'. Answering that question amounts to a paradigm shift of how we
>>> view housing and ownership - but realistically we have already experienced
>>> major shifts in how we use and 'own' homes that have yet to be designed for
>>> and provided for.
>>> On average we occupy a home for less than ½ a day and most of that is spent
>>> sleeping (8.6 hrs on average). As a designer that tells me that a 'home' has
>>> to be ideally quickly responsive in terms of providing hvac and other
>>> necessities (hot water, aesthetics, views(?), daylighting(?). So however we
>>> fit individually into those averages our community as a whole does fit into
>>> that. Our community may occupy our home before and after us (we tend to move
>>> a lot as well) - so we are designing buildings that basically have to look
>>> after themselves for 1/2 the day without the benefit of our presence. Does
>>> PA, NZE provide for social occupancy or does it provide for the building in
>>> itself?
>>> A final comment is about scale. As a designer I've worked to minimize
>>> footprints and that is where a designer can excel in making a small space
>>> work. Ironically small homes as a single footprint are very wasteful of the
>>> materials, structure and systems needed to support them. Rowhouses,
>>> multistory strata and cohousing are much friendlier solutions.  
>>> 4465 UPHILL RD,. DUNCAN, B.C.  CANADA, V9L 6M7
>>> PH 250 748 7672 FAX 250 748 7612 CELL 250 246 8541
>>> terrain at shaw.ca
>>> -----Original Message-----
>>> From: greenbuilding-bounces at lists.bioenergylists.org
>>> [mailto:greenbuilding-bounces at lists.bioenergylists.org] On Behalf Of David
>>> Posada
>>> Sent: January 10, 2011 12:43 PM
>>> To: 'greenbuilding at lists.bioenergylists.org'
>>> Subject: Re: [Greenbuilding] Aggressively Passive: Building Homes to to the
>>> Passive House Standard
>>> There was a long and lively discussion recently on the PHNW group list about
>>> how the PHPP spreadsheet treats on-site PV vs on-site Solar Hot Water, the
>>> rationale behind the PE factor of  0.7, and an analogy of grid-tied PV
>>> generation can sometimes be more of a "carbon offset:" 
>>> http://groups.google.com/group/PassiveHouseNW/browse_thread/thread/4e76b643b
>>> 2310a6b#
>>> On a less technical note, when you hear glowing praise for PH from some
>>> corners, frustration and discontent from others, I'm reminded of the maxim
>>> "if all you have is a hammer, everything looks like a nail," and the
>>> inherent compromises of any tool. 
>>> Some standards and rating systems are rather blunt tools, others far more
>>> precise. It seems the more precise and accommodating a tools is, the more
>>> difficult it can be for lay-people to learn and apply. 
>>> For an engineer with many tools in their kit, and the wisdom to know the
>>> limitations and best practices for each one, they can make good calls on
>>> when one approach makes the most sense, and when it is requiring less
>>> meaningful effort. 
>>> For others, the nuances may be less clear or important, and they see a
>>> particular tool such as Passive House as being for them the most appropriate
>>> means to an end. 
>>> Part of the challenge is with so many tools vying for our attention,
>>> support, and dollars, their developers, promoters, reviewers and critics
>>> have to make countless assumptions and compromises both to make the tools
>>> useable and to explain them to the world. With the shifting fortunes of
>>> praise and popularity is easy to see how a lot of money, respect, and pride
>>> is at stake. I think it can be especially frustrating for people who have
>>> dedicated years to advancing better understanding of building systems to see
>>> the public's eyes glaze over and reach for the latest shrink-wrapped
>>> package. 
>>> These comments from a new member may seem obvious or off-topic, but I felt
>>> compelled to offer them out of my own disappointment in watching how the
>>> conversation sometimes goes downhill when the value/ relevance/ worthiness
>>> of PH or LEED are being debated in different forums. We all love a good
>>> discussion and learn a lot from the debating the details, but I think
>>> something can get lost in the fray. 
>>> I don't think this is a problem in this group, or limited to just the PH
>>> topic - people are exceptionally good here at clarifying their assumptions,
>>> finding common ground, and not taking blustery conclusions personally.  
>>> When we venture outside of this circle as advocates and ambassadors for
>>> green building, I just wanted to make one proposal: I think we can be more
>>> effective at promoting a more responsible built environment if we
>>> acknowledge the common purpose of different tools, the inherent compromises
>>> of any approach, and how the balance of these strengths and weakness work
>>> for different contexts. Apologies if this sounds too idealistic or preachy. 
>>> David Posada
>>> Portland, Oregon
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j> John Straube
j> www.BuildingScience.com

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