in pursuit of energy efficient minimalism
There are a number of things we like about the Living Building Challenge (LBC). First, it’s the most stringent ‘green building’ program around. It picks up the slack where programs like LEED unbelievably strayed in the first place. Second, and probably more importantly, it isn’t influenced by the whimsical marketing gimmicks of industry – and this is actually one of the reasons we are big proponents of Passivhaus, as well. Third, it’s insanely hard. If you thought Passivhaus was tough, LBC is even crazier. There’s a reason there are only three fully certified ‘Living’ projects…
The good bits about LBC are definitely praise-worthy. As urbanists, we wholly agree with the intent to limiting growth/development, aiming for net zero water and healthy buildings. A 1:1 land exchange to protect development in perpetuity is an idea that we love, and not as expensive as one would think. And while Seattle’s a city that makes living sans cars (especially with kids) difficult given our topography and uber pathetic transit system – there are options, including zipcar (which we do use).
However, the Energy and Materials petals – especially in the billing of LBC as a restorative or regenerative standard – need to be revisited. [Warning!!! energy nerd ramblings ahead]
07 Net Zero Energy
‘One hundred percent of the project’s energy needs must be supplied by on-site renewable energy on a net annual basis.’
The problem with this petal is site net zero is only ‘emission/pollution free’ for buildings on batteries. That is, due to grid inefficiency, transmission losses, grey energy, etc., solar PV or wind are not zero emissions!
Frankly, net zero energy is ‘magical electron math’ at best. This is further compounded by a ridiculous boundary condition imposed on LBCs. As Nick Grant (who recently wrote a great bdonline article on the ridiculousness of ‘zero carbon’ buildings) stated at the Passivhaus conference last May– the actual boundary condition for net zero buildings isn’t the building or the legal site, it is the earth.
This has significant implications – for one, the Bullitt Center (which we previously blogged about) would have a smaller PV if it met Passivhaus. There’d be no need to fudge the legal site boundary and thrust a ginormous PV array into the public domain. Second, if the ‘earth’ is the site – then energy to offset what a building consumes in Seattle could be produced in a more optimal location. In our opinion, building planners should be responsible to get the demand down as low as possible. Then, energy production (and improving the overall grid) can be dealt with on a grander (and significantly more cost-effective/greener) scale. No brainer…
Regardless of boundary, if we’re going to claim ‘emission free’ buildings, then gosh darn it – we should at least be honest! And if we’re talking about regenerative or restorative standards with on-site renewable – shouldn’t we be building plusenergie/carbon reducing buildings like Rolf Disch’s Solarsiedlung in Vauban (answer: yes!)?
12 Embodied Carbon Footprint/14 Appropriate Sourcing
My critique of these two petals is intertwined. First, by not allowing superior high performance products from longer distances – the building’s overall performance can suffer –in some cases, significantly. We’ve talked about the issue of EU windows saving carbon in a Passivhaus, and that same argument applies to other components (e.g. HRVs). Presently, there are companies in the EU making HRVs/ERVs with upwards of 95% efficiency – even on the commercial side. To use an inferior local product means an increase in the embodied carbon footprint of the building to offset the lack of performance. In many cases, this increased embodied carbon footprint can be responsible for the production of much more CO2 than simply importing the component from farther away. To me, this doesn’t make any sense.
Put it another way – with items that contain ‘red-listed’ ingredients but no alternatives exist – it is possible to allow their use by writing the manufacturer a letter that basically states, ‘your product sucks environmentally, so hopefully you will do something about it’. So why can’t we do the same thing for products manufactured further away?
Dear Regional HRV manufacturer,
I really wanted to use your product and support local business, but the Dutch make an HRV that is 50% more effective in heat recovery efficiency than yours and has a much lower fan consumption. So, I’m going with them for now, as the transportation CO2 is far lower than the added embodied carbon I would have to add to the building with your product – plus I can reduce the size of my PV, actually reducing costs AND embodied carbon of that element. Sooo yeah, perhaps you can engineer a better product as we would love to use it on our next LBC project…
Frankly, I think that kind of letter would have a much more rapid effect, no? If we’re going to purchase a carbon offset for the construction footprint of the building (if you really want to get nerdy, add transportation CO2 as well, which can add up rather quickly), does it really matter if my windows are manufactured in Minneapolis or Austria?
Lastly, there is a requirement for energy monitoring, but nothing in place for quality control or commissioning of buildings. What this means is projects attempting ‘Living’ status may be far from what we would consider ‘high performance’ – poor insulation installations, thermal bridges galore, poor windows. And so to make up for this lack of performance – even more money needs to get thrown on the production side resulting in uber expensive/oversized PV systems. This was the case for the Tyson Living Learning Center. The project wasn’t even commissioned until several months into occupancy! Via the DJC…
“The first step was to commission the systems and to perform heating, cooling and building envelope audits to assess infiltration, insulation, and system design and performance. As part of the commissioning a blower door test showed there were areas of the exterior walls and ceilings that were missing insulation, and that air infiltration through the building envelope was a significant issue.”
After the envelope deficiencies were addressed, additional PV panels were added to ensure the project would produce enough energy to meet LBC. Good Grief, Charlie Brown!
For us, this is where Passivhaus can have a significant impact when incorporated into the Living Building Challenge. It’s the quality control needed on the energy/envelope performance side. It helps to attain the Healthy Air petal (meh, ASHRAE62.2…), the Civilized Environments petal (commercial PH projects usually have high daylighting levels), the Inspiration & Education petal (International Passivhaus Days) and Rights to Nature petal if designed properly. While we do have some concerns, we would be thrilled for the opportunity to design an LBC. I think we’d rock it (much like we did our Atka LBC proposal) – and of course we’d have to open source it!
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