Nuthatch Hollow Goes for Both Passive House and Living Building Challenge. This Is Hard.

Nuthatch Exterior

UPDATE: After writing this post I was contacted by the International Living Future Institute, which took issue with some of my statements and provided clarification. The Living Building Challenge is the toughest green building standard and I clearly had some misconceptions, but I am not convinced by all of their responses. So I am generally leaving my post as it was, showing where I was wrong, and adding comments from Brad Kahn for further discussion.

Ashley McGraw Architects make a whole new challenge for themselves.

Getting Passive House certification for a building is hard; you have to design it for really low energy consumption and air infiltration, and need to have really good quality windows. Getting Living Building Challenge certification is REALLY hard; it might well be the toughest building certifications there is, which is why it is so often called "aspirational." With the LBC you have to worry about the seven petals: Site, Water, Energy, Health, Materials, Equity, and Beauty. Sometimes they are almost impossible under current codes.

Nuthatch wall with windows

© Ashley McGraw

That's why I was so impressed with the little 2500 square foot lab and classroom, the Nuthatch Hollow Living Building, designed by Ashley McGraw Architects for Binghamton University. It was presented by Christina Aßmann and Nicole Schuster at the New York Passive House Conference recently. They are trying to certify the building for both Passive House (PHIUS) and Living Building Challenge, and the two programs don't always play nice with each other.

Nuthatch Hollow is an environmental learning and research site near the Binghamton University campus in Binghamton, New York. The purpose of this project is to design and construct a Living Building Challenge Certified environmental classroom and research facility on the grounds of Nuthatch Hollow. The facility will act as a hub for environmental classes and research within the broader Nuthatch preserve. At a symbolic level, the building will act as a physical manifestation of Binghamton University’s core values and mission, especially as they relate to preparing students to live effectively in a time of change and helping them actively create a more sustainable, resilient world.
Nuthatch Hollow Plan

© Ashley McGraw

As I mentioned, it is a little building, a lab and a multifunction room and some washrooms. But in the Living Building Challenge you can't have regular washrooms; you have to process all your waste on site, so many LBC buildings have composting toilets. These Clivus Multrum composters require lots of air to keep them from smelling, but Passive House buildings control the volume of air. So they have to put Heat Recovery Ventilators on the exhaust for the toilets and treat them as their own little separate world. (I asked why they couldn't run the toilet exhaust through the main HRV and was told that they were using ERVs or energy recovery ventilators, which can leak a bit.)

Then there are the materials used in the building. The Living Building Challenge has a "Red List" of chemicals that are not allowed. They range from PVC to neoprene to halogenated flame retardants (HFRS). But Passive House quality windows have lots of gaskets and components that are made of Red List chemicals. Foam insulations are full of HFRS. Many of the tools used by architects to achieve Passive House standards are almost impossible to use in Living Building Challenge. Navigating between the two must have been a nightmare.

BH: ILFI exceptions allow the use of HFRs in foam because of code requirements and since foam has such good performance characteristics.

Building section

Building section with Nicole Schuster/ Lloyd Alter/CC BY 2.0

The Living Building Challenge sets real restrictions on where you can build, limiting construction to grey fields, brownfield and previously developed sites. So instead of starting with a clean slate, they demolished most of an existing house on the site, and tried to keep as much of its foundations as possible. But Passive House requires serious insulation, often wrapping the entire building and foundation. It is probably easier and cheaper to do new. But here, the architects kept bits of wall, complicating the insulation significantly.

BK: Just because you cannot develop on a greenfield does not require the re-use of an existing building. That was a project team decision, not an LBC requirement.

The architects at Ashley McGraw have designed a lovely little building here, but the most interesting thing about it is the attempt to mesh two sometimes contradictory building certification systems. They have really had to work very hard at this, and the result is impressive. The problem is that these standards shouldn't be contradictory, but complementary.

It would be wonderful if all these certification systems were modular or plug-and-play so that they worked together. It might be a good start if the LBC people actually accepted Passive House for their energy petal instead of their net zero plus batteries approach-

One hundred and five percent of the project’s energy needs must be supplied by on-site renewable energy on a net annual basis, without the use of on-site combustion. Projects must provide on-site energy storage for resiliency.

Is there a battery on earth that meets the Red List criteria? Is there any requirement that the power taken from the grid is all from renewables? Does this scale? Does this even make sense? I am not so sure. On the other hand, Passive House has no red list; you could insulate with HFRS treated baby seal fur and it would be fine.

BK. Yes, there are many batteries that are Red List compliant. No it would not be either realistic or possible to require power from the grid to be all renewable. Yes, LBC scales, as exemplified in current multi-family affordable housing projects, huge corporate campuses and scaling across whole retail portfolio's.

Nuthatch multipurpose room

© Ashley McGraw

Perhaps there should be a meeting in that multipurpose room at Nuthatch Hollow and figure out how to resolve all these contradictions.

UPDATE: I have left my original comments and notes visible for a number of reasons. 1) this is complicated stuff and I sometimes get things wrong, for which I apologize and which I am not going to hide. 2) I still believe there are issues to be debated and discussed, (such as not going foam-free) and hope to pick up on these with further discussions with the International Living Future Institute. Watch this space.