in April we went and checked out this year’s California Straw Building Conference. We loved every second of it and wish you could’ve gone, but this report will have to do. We hope the buzz and excitement for the future of building is conveyed here, and we’ll do some deeper dives on the topics discussed in the coming issues.
It’s Friday afternoon and you’re driving over the Golden Gate bridge, on your way through the rolling hills of Marin County to the wine country in Sonoma, California. Countless people have headed this way before, taking in the cool springtime bay gusts and dramatic views, but far fewer people have gone to your precise destination. Where is that?
The 2022 conference of the California Straw Building Association (CASBA). You haven’t been here before, but the conference has been held at the Westerbecke Ranch several times before. In a previous year attendees built a straw bale and earth plaster bell tower that stands proud to this day. You’ve heard that this is the gathering to go to if you want to learn about where the natural building movement has been and where it’s going. CASBA has been around since 1996; it was one of the first natural building advocacy and research groups. Many builders, engineers, architects, and other enthusiasts got together to figure out how to build in a healthy and resilient way. You’re excited to meet some of the people that have been involved since the start of the revival, your eagerness increasing as you turn down the gravel road and weave through small farms. You park in the gravel lot beneath an old oak tree, get out and take a deep breath of crisp fresh air. This evening’s presentations, like all the other ones this weekend, take place in a large room with doors left open at two sides. This transforms the room into an outdoor pavilion that’s still dim enough for a projector screen to glow. The night air feels so nice as a little breeze passes through the room. Between the natural ventilation, outdoor views, and mix of regular and lean-back-on-the-floor chairs, you feel the most ready for a string of lectures and discussions that you’ve ever been. There are no screens on the fully opened doors and windows of the lecture hall. There seems to be no fear of the mosquito swarms that you’re used to back home. As you look up from your notebook, getting that stellar straw bale pun down on paper, you see something you don’t believe is real. A second glance reveals that it is a bat that just flew in, darting around the ceiling. A few people glance up briefly but most people don’t seem to care and focus back on the presentation. You’re not surprised that a bat flew in, what’s unbelievable is that no one is bothered or scared. The bat leaves with no issue a few minutes later. This is when you realize that the group of people around you are the kind of people you want to stick around. After the 5×5 presentations, where each presenter shows five slides in five minutes, the beer and wine comes out for after-hours discussion. There’s no bonfire, but it feels like there might as well be, based on the tone and warmth of the people you hang out with. Each meal flows from the presentations almost seamlessly. The breakfast/lunch/dinner bell rings, and you and the attendees gather around big tables outside and pick up where you left off. The tables are big enough that no cliques form, and you feel comfortable sitting at any table. Tonight the 5×5 presentations transition to the only appropriate thing to have at a natural building conference on a Saturday night: an hours-long dance party with people of all ages. Afterwards, you hear someone turned on the ranch’s hot tub, which sounds really nice right now.
“I felt like I was floating, but also on the ground. I was alone but there was a presence all around me”. Someone’s talking to you in the hot tub about riding a bike through a sand storm. Eventually the water gets too hot and you leave, wondering where the closest sand storms are to you. The walk from the hot tub to the sleeping rooms is a great wind down; you’re guided by low dim lights up the gentle hill, accompanied by countless frogs. The last presentation ends. Laura Bartels comes back up to the front of the room. She leads everyone in a mindfulness exercise to finally close the conference. You’ve never tried an exercise like this before but it really works for you. After this and one more communal meal, the future seems bright. Not in a shiny everything-will-be-okay kind of way. But you feel like you have real capable allies in the fight for a survivable future.
Emerging Designers in the Low-Carbon Scene
At CASBA 2022 one of the most exciting presentations was from three graduate architecture students from the University of California-Berkeley who took on an independent study in natural building. The three students: Tya Abe, Cari Hartigan, and Rachel Tove-White. They found common ground in a talk that Massey Burke, co-director of CASBA and one of the primary organizers of this conference, gave on buildings and carbon at Berkeley in 2018. “It was nice to realize, like, oh there are other people who are frustrated with the lack of environmental sensitivity in this program,’’ Tya remembers. Frustrated that their curriculum was not providing any tools to learn about natural and alternative building methods, the three students took their education into their own hands and created a graduate independent study program. Tya, Cari, and Rachel planned the schedule, wrote the syllabus, arranged the lectures, and organized some hands-on build days all by themselves. Cari noted “What was initially so exciting to me is learning that this isn’t just something alternative, [something] off the grid that you can only do at certain scales…We’re finding out techniques that can be applied to lots of different types of projects”. These three carried the lessons from their independent study into their thesis projects for the year, each drawing on different aspects of sustainability and natural building. These projects turned out well, even though many times these students knew more about natural building than their professors did. “We looked into whether other universities had natural building classes that we could model our syllabus after and we couldn’t find much, so we thought this class could become a good model,” said Rachel. This panel started a spirited conversation with the audience about the state of design education in the United States, and how the audience wished more students were doing what these bright young Berkeley grads did.
Carbon Sequestration with Natural Materials
Massey Burke gave a compelling speech on the position of straw in the world of carbon emissions. According to Massey, embodied carbon, which is the carbon emissions associated with the making and transport of materials, “is one of our most powerful tools for talking about why the natural building movement makes sense.” Straw sequesters carbon because grains and grasses are “natural carbon storing machines” and store carbon more efficiently than even wood or other more conventional construction materials. She spoke about the life cycle analysis that CASBA has been putting together for straw bales, which will give a set of data for people using straw bales to directly compare to other construction methods. This will be a huge step forward for advancing straw bale construction even further into the mainstream. Massey’s speech showed the potential for straw as a front-runner in the evolving conversation of alternative construction materials on a large scale. CASBA’s research also involved a fascinating exploration into using regenerative farming practices to produce straw for construction. This would dramatically change the environmental impact that comes from the farming side of straw bale creation. We’re excited for more information on these research projects coming from Massey and CASBA soon!
Pre-Fabricated Straw Panels in Development
The Strawtegi panel by Susan Klinker was the first panel presented. The panel itself is made with commercial bags of chopped straw that are packed into a wood frame structure at around 8lbs per cubic foot and sheathed on both sides with wood fiberboard. Susan is using this 12” thick panel in an ADU in Salt Lake City. Once completed it will be the first permitted chopped straw building in the United States.
The Gryphon panel by New Frameworks is “like a stud framed wall really, but it offers potential to scale up” said Lindsey Love, of Love Shack Architects. She doesn’t represent Gryphon Panels but is using them in a project in Vitor, Utah currently. These 16” panels are similar to standard construction materials, and include an Intello smart membrane. They are prefabricated and require machine installation.
The Boa Constructor panel is an even more conventional way of panelizing straw bale construction. Their goal was to have a bale structure panel that mirrored something that is typical in the wood frame world. These panels are made of bales cut along the length, and fitting them cut edge to the inside in a 2’ or 4’ wide wood-framed box with sheathing on the exterior. The 12” thick panels were tested on a home-build in Santa Cruz. They were built off-site and set in place by hand, though, because of their simplicity and use of standard materials, they could be built anywhere. This panel is a collaboration between Boa Constructor and Verdant Structures.
Verdant Structures out of Berkeley is using an EPA small business grant to develop what they’re calling an S-SIP, or a straw structurally-insulated-panel. “We have 16 people, so we’re one of the largest natural building engineering firms in the country. I thought maybe we should apply for this grant” said Anthony Dente, one of the owners of Verdant. “Existing SIP insulation materials are high in environmental carbon” so using straw seemed like a natural solution. In addition, according to Verdant “We can increase the thermal efficiency of straw by two-times what’s credited for bales… that’s why we’re planning on getting down to a 2×6 wall equivalent.” This panel is currently still in the design phase, with some testing being done at UC Berkeley.
