An Update from the New Gravity Housing Conference

Lisa White, PHIUS+ Certification Manager

This past week I had the opportunity to visit Philadelphia and attend the first annual New Gravity Housing conference, hosted by the Delaware Valley Green Building Council (DVGBC) in partnership with the Greater Philadelphia Passive House Association (GPPHA) and Philadelphia Collaborative.

The Pennsylvania Housing Finance Authority (PHFA) wrote passive building into their 36345506521_044a0a22a9_z application for tax credits in 2014. That spark ignited significant growth in the passive building market of Pennsylvania and opened the eyes of other finance authorities to jump on board this effort, which has brought a momentous shift in the affordable housing market. The energy surrounding that was evident at this conference; it was quite inspirational.

The discussion didn’t focus only on dollars and BTUs, but also around providing affordable, comfortable, resilient, efficient and healthy housing to low-income residents. As a lunch keynote, Jonathan F. P. Rose, author of The Well-Tempered City, inspired the audience to connect affordable housing with cultural, health and educational centers.

We also heard from many great project teams — some who have worked on multiple passive projects, and others who were tackling it for the first time. Regardless of the level of experience project teams had, there was a noticeable sense of excitement and passion for what they were doing. That was great to see.

Alongside the optimistic dynamic, there seemed to be a few consistent questions from the audience, mainly: 1) How much does it cost, and 2) Will these buildings really perform? — show me the data.

I’m happy to relay many PHIUS+ project teams reported a very low additional cost to get to passive relative to how they’d typically build. Specifically reported on was Elm Place, a recently PHIUS+ 2015 certified 30-unit multifamily project in Vermont, achieved with only a ~1-2% increase in cost.

Hank Keating and Lauren Baumann provided monitored data from their “passive-inspired” (not certified) 160 unit development, showing significantly lower EUIs for these buildings relative to the LEED Gold townhomes they also monitored.

CaptureKatrin Klingenberg and I reported on monitored data from four of the first affordable multifamily passive building projects and, overall, we’re happy with the results. While our findings confirm the notion that all occupant behavior can’t be predicted, however, when it comes to the average occupant or residence, these projects are quite close to hitting their expected energy use targets. The data from Orchards at Orenco Phase I shows in terms of overall annual energy use, the WUFI Passive energy model prediction came within 2% of the total energy use than was actually measured. However, other projects showed a larger gap. As we continue to collect data, we’re using it to continue developing our energy modeling protocol and calculation methodology. Our goal is to predict energy use as accurately as possible in WUFI Passive so we can be realistic about expected performance and potential savings in PHIUS+ projects.

Galen Staengl presented various innovative mechanical system designs for multifamily passive buildings across the country. Scott Pusey provided great insight from the field from the role of a PHIUS+ Verifier, and the best practice processes his firm has developed over time from their experience. In her keynote, Lois Arena presented that finance agencies in 11 states now have written passive building into their incentives in one form or another.

Zach Semke provided an inspirational closing on the impact renewable energy will play in the future. He exposed the unpredicted and unprecedented investment and deployment in worldwide solar energy capacity this past year, and spoke about how, like solar energy, passive building is a technology and therefore poses the opportunity to follow the exponential growth curve that technology follows.

I imagine there will be many more conferences like this around the nation soon. The sharing of knowledge, positive and negative experiences, as well as the ability to disclose what might be done better the next time around, is critical to the advancement of passive building.