The Perlita Passive House Journey Part III: Green Building Certification
By Sofia Siegel
Part III: Perlita House Green Building Certification
While we’re out here trying to beat the heat, construction on the Perlita Passive House continues on schedule. By now you’re familiar with the Perlita Passive House design process (and if not, you can read Part 1 and Part 2 to catch up) and have read that Verdical Group is leading the charge on the Project’s Living Building Challenge (LBC) Energy Petal Certification. But what does that really mean?
Green Rating Systems:
Even for Green Building consultants, the many Green Rating Systems can get confusing. LEED, Living Building Challenge, WELL, FitWel, Green Globes, SITES, Passive House – it’s a lot to keep track of! Not every rating system is right for every project or project team, and the variations between them mean that even a highly efficient, well-designed project is not guaranteed the highest marks across all rating systems.
Perlita House – Beyond Passive:
Xavier Gaucher, the homeowner and Passive House champion, began this project knowing he would be building to the Passive House standard; he sees this as the most efficient design framework, and best starting block. Design driven and performance verified, the projected energy use onsite is far below that a baseline building of the same size. Energy production and consumption have hugely negative impacts on the environment, extending beyond just the carbon dioxide released when fossil fuels are combusted. Particulate Matter and VOCs are released along with greenhouse gases during combustion; a massive amount of water is used in fuel extraction and refinement, and in generation as well (devastating in our drought-restricted Southern California); pipeline leaks barely make headlines while they destroy whole aquifers; the list goes on. And while clean renewable energy from wind and solar help offset that damage, the best results still come from using less. And for Gaucher, a Passive House was the logical first step in designing his new home.
But sustainability doesn’t stop at energy use reduction. The house would need to be a healthy space for his family to live and grow, but how to best manage that?
Gaucher and Verdical Group connected around the Living Building Challenge in September of 2016, and along with experts in Landscape Architecture, sustainable materials purchasing, and engineering, we reviewed the design and completed a feasibility assessment for Living Building Challenge.
Perlita Passive House LBC Kick-Off Meeting
If you’re not familiar with Living Building Challenge and the International Living Future Institute, they have a beautiful website here, but in their own words LBC is the “world’s most rigorous proven performance standard for buildings.” Instead of levels of certification like LEED (Certified, Silver, Gold, Platinum), LBC projects complete one of three certification pathways: Full Living Building, Petal Certification, or Net Zero Certification. LBC is comprised of seven interrelated Petals (categories addressing sustainability) that work together to contribute to the overall efficiency of the project and well-being of occupants.
- Full Living Building Certified complete all 7 Petals, with the 20 related Imperatives, and provide 12 months of energy data to prove the project is Net Positive (generates 105% of their annual energy use onsite without the use of combustion).
- Petal Certified Projects start with one base Petal (Energy, Water, or Materials), complete all related imperatives, and two other full Petals. All Petal Certified projects must also complete Imperative 01. Limits to Growth and 20. Inspiration and Education
- Net Zero Energy Building Projects focus solely on energy efficiency. In previous iterations of LBC, Net Zero Energy projects were required to complete imperatives 01 and 20 as well, but now the requirements are strictly performance based: generate 100% of the project’s annual energy onsite, without the use of combustion
After reviewing the Petal Handbooks, and investigating the LBC project requirements, our team found many components were already fulfilled by the site selection and Passive House design framework, and we found some immediate challenges as well. The site is previously developed urban infill, meeting the first Imperative “01. Limits To Growth.” The Energy Petal requires that a project generate 105% of their annual energy consumption on site; the super-efficient passive house would be well-situated to meet this challenge with a reasonable PV array, because the building was starting from such an efficient place. However, battery storage requirements for resiliency on site were cost-prohibitive as written. A design feature visible from the street met the intent of the Beauty + Spirit Imperative. As we reviewed all of the requirements and strategies, we concluded that registering the project as a Net Zero Building would be highly achievable, but that Energy Petal Certification would be the more ambitious route, with guidance from ILFI.
After some discussion with ILFI about the Battery Storage Requirements, ILFI issued a dialogue to allow for onsite renewable energy to contribute to the resiliency battery storage requirements, and the project team forged ahead with registering the project for Energy Petal Certification.
Like Passive House, Living Building Challenge Certification is contingent on performance, and when the family moves in to the completed house (September 2017), they will have to submit 12 months of energy data, alongside documentation of the Energy, Health and Happiness, and Beauty Petals. Verdical Group’s Holly Hill and Sofia Siegel are hard at work tracking this process, and will steward the project through completion.
LEED For Homes
Because Verdical Group works in the LEED space so often, we couldn’t help but wonder how this project would compare. What would this look like as a LEED for Home project? How would it fare under that rating system as designed?
So we completed an additional feasibility assessment. Reviewing the design strategies and construction pathway, determined by Passive House and Living Building Challenge, how would a Net Positive, water efficient, well-specified healthy home measure up to a system it was not designed for?
And we learned a lot! The site selected gave the project access to many points in the Location and Transportation Category (urban infill, adjacent to many community resources and ample open space). The Net Positive design suggests that the project would receive full marks in the Annual Energy Use category. Efficient fixtures and landscape designed without irrigation resulted in full marks for Water Efficiency. The products specified to comply with the Health and Happiness Petal corresponded with many of the LEED requirements, and the Project would achieve those too! We also found that LEED automatically awards certain points to Passive House Certified Projects, using PH certification to verify compliance for LEED.
However, even with all of these points, and all of the overlap, the project just misses the 80 point threshold for LEED Platinum. While Passive House sets ambitious energy efficiency goals, and Living Building Challenge Petal Certification addresses a diverse set of sustainability goals, the three rating systems don’t line up 1:1:1. Without any changes, the Perlita Passive House is on track to LEED Gold equivalence, and with some changes (especially built in to the process earlier, had the project been pursuing LEED from the beginning) it would have been feasible to get to the 80+ points needed for Platinum equivalence. The three rating systems work in concert with each other, but one certification does not guarantee the brass ring in another.
While we continue to pursue LBC Energy Petal Certification, and track construction progress through the end of the summer, we have found it valuable to think about the project from different perspectives. How would we have done this differently to meet LEED requirements? Would the building be more sustainable if we had that additional lens? Which rating system creates the most impact on an individual project? On the market at large?
In the end, Gaucher selected Living Building Challenge Petal Certification to accompany his Passive House Certification because it most closely aligned with his goals. And Perlita Passive House is being completed at a time when there are no Energy Petal Certified Homes in Southern California. This project is unique in the region, and serves as a teaching tool to accelerate sustainable building practices in the market. But the high number of points feasible from LEED show more similarities than differences between the two rating systems, and Passive House, LBC, and LEED are all working toward the same goals; leaving the world cleaner and more beautiful than we found it.