Why is Katrin Klingenberg proposing to water down the Passivhaus standard?
“The Passive HouseA residential building construction standard requiring very low levels of air leakage, very high levels of insulation, and windows with a very low U-factor. Developed in the early 1990s by Bo Adamson and Wolfgang Feist, the standard is now promoted by the Passivhaus Institut in Darmstadt, Germany. To meet the standard, a home must have an infiltration rate no greater than 0.60 AC/H @ 50 pascals, a maximum annual heating energy use of 15 kWh per square meter (4,755 Btu per square foot), a maximum annual cooling energy use of 15 kWh per square meter (1.39 kWh per square foot), and maximum source energy use for all purposes of 120 kWh per square meter (11.1 kWh per square foot). The standard recommends, but does not require, a maximum design heating load of 10 W per square meter and windows with a maximum U-factor of 0.14. The Passivhaus standard was developed for buildings in central and northern Europe; efforts are underway to clarify the best techniques to achieve the standard for buildings in hot climates. is not a brand, it is a building concept which is open to all.” – Anton Kraler
I have to say, I completely agree with Kraler. I don’t view Passive House as a brand, but a concept that belongs to the greater built environment (Passivhaus is a greater good!). And as a concept, I find it very sound and worthwhile. So it was interesting to be forwarded the inaugural blog post from the PHIUS blog, Klingenblog (I’m not making that up!).
Yes, PHIUS has jumped on the PHlog (Passivhaus+Blog) bandwagon, and the first post seems a prelude to opening Pandora’s box and watering down the standard. Fresh off being criticized for merely questioning the implications of banning certain products that would influence maybe 2 or 3 projects/year, I find this line of thinking to be in the same vein.
Should the standard be relaxed for buildings in extreme environments?
Katrin calls for letting go “of the illusion that there is a God-given magical number that can cost-effectively be adhered” (the 15kWh/m2a) – that the cost of “meeting the mark” in certain climates is both problematic and costly. This is due to the “difficulty” (perceived and real) of achieving Passivhaus in extreme environments (especially for single-family houses or small buildings). We don’t view this as a flaw – in fact, this is the inherent aspect of Passivhaus that makes the most sense to us, plus our belief that there are no small-house penalties, only bad design ones. Call us purists, we honestly don’t mind!
Relaxing the standard in extreme climates also seems to give blessing to maintaining the status quo instead of addressing the structural problems of said extremes. Maybe any single-family home, Passivhaeuser included, in isolated, über-cold climates can’t truly ever be sustainable. Indeed, maybe in extreme environments, buildings should cluster together for warmth and affordability (across a number of scales).
Drawing conclusions from only 100 buildings
Regarding process, Kat writes, “PHIUS is proposing to the PHIUS Tech Committee — composed of industry and policy leaders from the United States and Canada — to leverage the PHIUS dataset of 100 buildings, and to solicit feedback from the consultant community to create a new protocol that will allow Passive House professionals to determine practical modifiers to the standard to address climate, small home and retrofit scenarios.” I see two parts to this – first, it’s good to see there will be oversight on something like this, and second (and probably even more important), consultant buy-in/feedback. EnerPHit seems to address the PH retrofit question rather well. It’ll be interesting to follow this process.
There also seems to be an inherent liability in utilizing the first 100 projects (buildings?!?) given that a number of these were probably shoehorned. Plus, after building the first – the process is streamlined and optimized – there is a significant learning curve! Finally, and perhaps this is jumping the shark, but revisiting the standard with a very non-representational sampling seems premature, and would potentially be better served at 500 buildings or when more consultants have built and/or certified several projects.
On some level, I see relaxing the standard as an “out” for product manufacturers needing to developing better performing products or getting consultants/designers to work hard to really optimize their projects. It also doesn’t force folks to deal with the hard philosophical questions that may be worth asking.
Looking hard at where we live
If PHIUS is going to claim consultants should be auditing embodied energyEnergy that goes into making a product; includes energy required for growth, extraction, and transportation of the raw material as well as manufacture, packaging, and transportation of the finished product. Embodied energy is often used to measure ecological cost./carbon in projects (which we completely agree with) – then maybe we should also be taking a really hard look at how and where we live. After all, food and transportation can significantly affect one’s overall CO2 footprint – especially in extreme locales, and especially in low-energy homes.
So are we unbending purists? Nattering nabobs of negativity? I’d like to think we’re just asking the difficult questions that deserve some face time. What do you think?
Mike Eliason is a designer at Brute Force Collaborative in Seattle, Washington.
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