‘BIO-BASED AND EARTHEN ARCHITECTURE’ AIA LA X RRC WEBINAR SERIES
BIO-BASED AND EARTHEN ARCHITECTURE’ AIA LA X RRC WEBINAR SERIES
In collaboration with The Regenerative Rebuild Collective, AIA|LA brings to you a series of webinars to explore best practices in bio-based and earthen architecture.
Earthen and bio-based construction materials have been successfully utilized for millennia in climates similar to Southern California’s, and modern engineering has further demonstrated their safety, structural viability, and environmental benefits. These materials exhibit inherent fire resistance; are carbon-beneficial or carbon-neutral; have the ability to actively filter interior environments; do not require chemical additives such as flame retardants, solvents, or heavy metals to achieve high performance metrics; and can be manufactured from local or regional soils, fibers, and aggregates.
Despite the myriad benefits, and due to the systemic failures of our society, architects in Southern California are either unaware of their existence or lack the knowledge to incorporate these materials into safe, scalable, and innovative architecture. This 8-part webinar series brings together some of our industry’s leading professionals to showcase how these materials are being implemented and how these materials can help us achieve a lower-carbon and healthier built world.
The Regenerative Rebuild Collective (RRC), in collaboration with AIA | LA Building Performance & Regulations Committee (BP&R) and the Committee on the Environment (COTE), brings you a webinar series diving into the world of bio-based and earthen architecture.
The series starts September 9th, with webinars running each Wednesday at 10 am (PDT) / 6 pm (GMT+1) through October 28th.
Week 1: Sep. 9th – WHAT IS BIO-BASED AND EARTHEN ARCHITECTURE?
Week 2: Sep. 16th – STRAW
Week 3: Sep. 23rd – EARTHEN BLOCK
Week 4: Sep. 30th – LIGHT STRAW CLAY AND COB
Week 5: Oct. 7th – HEMPLIME
Week 6: Oct. 14th – BIO-BASED AND EARTHEN FINISHES
Week 7: Oct. 21st – IMPLEMENTING BIO-BASED AND EARTHEN ARCHITECTURE AND STRUCTURES
Week 8: Oct. 28th – LEARNING FROM EUROPE
REGISTER ON ZOOM: Attend as many of the series as you have time to join!
CLICK HERE to learn more about the Regenerative Rebuild Collective
SCHEDULE
9/9 WEEK 1: WHAT IS BIO-BASED AND EARTHEN ARCHITECTURE?
An introduction and overview of bio-based materials, their benefits, and preference among end-users.
Leigh Christy, FAIA, LEED AP BD+C – Principal, Perkins & Will
Luke Lombardi – Associate | Building Performance, Buro Happold & Co-lead, Carbon Leadership Forum (CLF) Los Angeles Hub
Dr. Arta Yazdanseta – Assistant Professor, Rensselaer Polytechnic Institute’s School of Architecture
9/16 WEEK 2: STRAW
An introduction to straw bale and straw-panel architecture.
Anni Tilt, AIA – Principal, Arkin Tilt Architects
R. Gavin Knowles – Principal + Founder, Knowles Architect
Paul Lewis, FAIA – Principal, LTL Architects
9/23 WEEK 3: EARTHEN BLOCK
An introduction to Adobe and CEB architecture, and earthen finishes.
K. Ben Loescher, AIA – Founding Principal, Terrain
Godfrey Riddle, MPA – Founder & President, Civic Saint
9/30 WEEK 4: LIGHT STRAW CLAY & COB
An introduction to light straw clay and cob architecture.
Sasha Rabin – Founder, Earthen Shelter
Steve Goodhew – Professor of Environmental Building and Discipline Leader, School of Art, Design and Architecture, University of Plymouth
10/7 WEEK 5: HEMPLIME
An introduction to hemp-lime architecture.
Caroline Dunn, AIA, CPHD – Founder & Principal, BIOBUILD
Dr. Eshrar Latif – Associate Professor at the Welsh School of Architecture, Cardiff University
Aaron Grail – Founder, Aaron Grail Construction
10/14 WEEK 6: BIO-BASED AND EARTHEN FINISHES
An overview of bio-based and earthen finishes available or in development.
Natalie Yon-Eriksson – Founder, Earth and Flax
Gina Ciganik – CEO, Habitable
10/21 WEEK 7: IMPLEMENTING BIO-BASED AND EARTHEN ARCHITECTURE & STRUCTURES
Anthony Dente, P.E., LEED AP – CEO, Verdant Structural Engineers
David Arkin, AIA – Arkin Tilt Architects
K. Ben Loescher, AIA – Founding Principal, Terrain
Wilfredo Paz Bermudez, P.E. –
10/28 WEEK 8: CLOSING – LEARNING FROM EUROPE
An overview of EU policy and successful projects.
Speaker TBC
2nd Speaker TBC
3rd Speaker TBC
SPEAKER BIOS
9/9 WEEK 1: WHAT IS BIO-BASED AND EARTHEN ARCHITECTURE?
Leigh Christy, FAIA, LEED AP BD+C – Principal, Perkins & Will
Leigh Christy, FAIA, LEED AP BD+C, is a Principal at Perkins&Will leading projects at the interface of architecture and urban design with underlying emphases on environment and engagement. She leads the global design firm’s Innovation Incubator micro-grant program and sits on its Research and Technology Councils. She also co-chairs the ULI LA Innovation Council, supporting the Urban Land Institute’s net zero carbon goals and exploring new methods to do so. Leigh graduated with degrees in architecture from the University of Michigan and the University of California, Berkeley. An adjunct faculty member of Woodbury University from 2008 to 2014, Leigh continues to sit on design juries and guest lecture at universities across the country.
Luke Lombardi – Associate | Building Performance, Buro Happold & Co-lead, Carbon Leadership Forum (CLF) Los Angeles Hub
Luke Lombardi stands at the forefront of sustainable practices in the built environment, leveraging his expertise as a structural engineer to influence materials, design, and construction to improve sustainability outcomes. As a leader in reducing embodied carbon, Luke actively contributes as co-chair of the SE 2050 program and co-lead of the Carbon Leadership Forum (CLF) Los Angeles Hub, which he helped establish in 2020. With a focus on innovation, Luke is committed to transforming both new and existing buildings, employing principles of circularity, strategic design, and mindful material selection to foster a more sustainable future.
Dr. Arta Yazdanseta – Assistant Professor, Rensselaer Polytechnic Institute’s School of Architecture
Dr. Arta Yazdanseta is a building physicist and Assistant Professor of Technology at Rensselaer’s Center for Architecture, Science and Ecology (CASE). She engineers bio-aggregate materials across three interlocking scales, spanning material chemistry, assembly design, and regional bio-circular supply chains, turning lab-tested properties into assemblies that manage energy flow and sequester carbon. A former SHoP Architects and hanrahanMeyers designer, she partners with manufacturers and builders to carry findings from bench to full-scale prototype. She holds a patent on a flatpack hempcrete formwork system, is co-PI on the DOE-funded HeRS project, and leads Habitat Atlas, proof that bio-based materials can be measured, trusted, and built at scale. Arta holds a Doctor of Design and Master of Design from Harvard GSD and a B.Arch from Pratt Institute.
9/16 WEEK 2: STRAW
Anni Tilt, AIA – Principal, Arkin Tilt Architects
Anni Tilt, AIA, is a principal of Arkin Tilt Architects. Three-time winner of the Acterra Business Award for the Sustainable Built Environment and numerous design awards, their work has been recognized and published nationally and internationally for excellence in design and sustainability. With a BSE in Civil Engineering from Princeton University, a M Arch from UC Berkeley, and as a founding member of the California Straw Building Association (CASBA), Anni aims to advance the intersection of architecture, engineering, and ecology. ATA has a portfolio of nearly 50 built straw-based structures – both residential and commercial – and has pioneered several hybrid straw bale wall systems pushing the envelope of climate-resilient building.
R. Gavin Knowles – Principal + Founder, Knowles Architect
R. Gavin Knowles, RA, is the Founder of Knowles Architect, Inc., a full-services architecture firm focused on the highly personalized and place-based design of residences, restaurants, and other facilities which celebrate their connection to the natural world and long-term land stewardship. His work integrates bio-based construction techniques to enhance the life of building occupants by creating bonds of affection between them and local ecologies while fostering bonds of economy between the building’s construction and local land communities. Prior to founding his own firm, Gavin was a Principal at Lundberg Design in San Francisco and a designer at William McDonough + Partners in Charlottesville, VA. He holds an M. Arch degree from the University of California, Berkeley and a B.S. in Architecture from the University of Virginia.
Paul Lewis, FAIA – Principal, LTL Architects
Paul Lewis, FAIA, is a Principal at LTL Architects based in New York City and Professor at Princeton University School of Architecture. LTL has received a National Design Award, the NY State AIA Firm of the Year, and has been inducted into the ID Hall of Fame. They are the authors of Manual of Biogenic House Sections (2022), Manual of Section (2016), as well as monographs Intensities (2013), Opportunistic Architecture (2008) and Situation Normal….Pamphlet Architecture #21 (1998). Paul received a BA from Wesleyan University and an M.Arch from Princeton University, and is a recent past president of The Architectural League of New York.
9/23 WEEK 3: EARTHEN BLOCK
K. Ben Loescher, AIA – Founding Principal, Terrain
Ben Loescher is the founding Principal of Terrain, a California architecture firm pioneering innovations in earthen construction, and founder of the advocacy group Adobeisnotsoftware. He recently designed and permitted California’s first two modern adobe homes and its first compressed earth block home under the International Building Code. A leader in code reform, Loescher successfully overturned an industry proposal to remove adobe from the building code and helped establish The Masonry Society’s Earthen Modular Masonry Committee to develop national structural standards. He has also served as Chair of the United States trade association for Earthen Construction and is active in Adobe in Action, a New Mexico-based earthen housing non-profit.
Godfrey Riddle, MPA – Founder & President, Civic Saint
Godfrey Riddle, MPA, is the Founder and President of Civic Saint, an innovative social enterprise disrupting traditional real estate through advanced alternative material science. An Echoing Green Fellow and Aspen Ideas Fellow, Godfrey stands at the intersection of spatial equity and climate-resilient architecture. Under his leadership, Civic Saint engineered the proprietary GeoNova™ compressed earth block (CEB) ecosystem—a low-carbon, modular masonry system manufactured from 90% local waste soil that recently achieved an accredited lab-verified compressive strength of 2,110 PSI, outperforming standard concrete. Driven by his background in architectural studies and public administration, Godfrey leverages circular-economy manufacturing to replace carbon-heavy construction with high-performance earthen sanctuaries called Stonehomes, establishing scalable, safe, and sustainable homeownership frameworks within historically redlined urban cores.
9/30 WEEK 4: LIGHT STRAW CLAY / COB
Sasha Rabin – Founder, Earthen Shelter
Sasha Rabin started her natural building journey in 2002, when she did an apprenticeship at the Cob Cottage Company. Since then, she has taught extensively with organizations such as The Yestermorrow Design Build School, The Canelo Project, Cal-Earth, The Solar Living Institute, and Quail Springs Permaculture. Teaching natural building has brought her as far as the Permaculture Research Institute (PRI) Jordan and PRI Kenya. Sasha is the Natural Building Advocacy Director for Quail Springs, sits on the board of the Cob Research Institute, and runs her own organization, Earthen Shelter. In the past decade, her work has pivoted to focus more on cob and earthen building testing, as well as building code and policy. She currently calls northern CA home.
Steve Goodhew – Professor of Environmental Building and Discipline Leader, School of Art, Design and Architecture, University of Plymouth
Professor Steve Goodhew leads the Environmental Building Research Group at the University of Plymouth. Steve initiated the CobBauge Project and researches into the sustainability and performance of buildings both new and historic. His main research focus is on the use of sustainable natural materials, particularly earthen walling systems. He specialises in upgrading the thermal performance of heritage buildings, maintaining their features. Steve leads the MSc in Low Carbon Architectural Engineering and is a Fellow of the RICS, CIOB and RSA.
10/7 WEEK 5: HEMPLIME
Caroline Dunn, AIA, CPHD – Founder & Principal, BIOBUILD
Caroline Dunn, AIA, CPHD, is the founder and principal of BIOBUILD, a design practice focused on biobased materials and low-carbon construction, based in Texas and California.
She serves as Co-Chair of the AIA Austin Advocacy, Resiliency + Climate Response Committee, where she led the effort to adopt Appendix BL (Hemp Lime) into the City of Austin building code. Her work centers on connecting design practice, building materials research, and policy to support the transition to lower-carbon buildings.
Dr. Eshrar Latif – Associate Professor at the Welsh School of Architecture, Cardiff University
Dr Eshrar Latif is an Associate Professor at the Welsh School of Architecture, Cardiff University, and a member of the University Senate. Trained in architecture, he is an architectural scientist specialising in sustainable building materials, building physics and bio-based materials and construction. His PhD examined the hygrothermal performance of hemp-based thermal insulation materials in the UK, forming the basis of his long-standing research on hemp-lime, hemp shive, cob and earth-based systems. His research grants include hemp-lime building monitoring, optimisation of hygrothermal properties of hemp-lime, development of hemp-wool bio-envelope systems, hygrothermal modelling, durability testing, and net-zero new-build and retrofit integrated with circular economy principles. He is co-author of Thermal Insulation Materials for Building Applications and has contributed internationally through keynote talks, technical committees, doctoral supervision and industry-facing research.
Aaron Grail – Founder, Aaron Grail Construction
Aaron Grail is a licensed California general contractor and founder of Aaron Grail Consulting and Construction, based in Sebastopol. Inspired by his grandfather — a structural engineer in San Francisco Aaron has been immersed in the building sciences his whole life, earning his GC license in 2004.
He is the first owner-operator of the EReasy hempcrete spray system in California, and specializes in bio-based and low-carbon building materials for residential and commercial projects. Aaron is an active advocate for natural building code adoption, a contributor to the Bio-Based Materials Collective and CASBA, and recently collaborated with Oregon State University on a hemp-lime spray demonstration and training event to advance hempcrete as a mainstream construction solution.
10/14 WEEK 6: BIO-BASED AND EARTHEN FINISHES
Natalie Yon-Eriksson – Founder, Earth and Flax
Natalie Yon-Eriksson is the founder of Earth + Flax, a Philadelphia-based company specializing in traditional, microplastic-free, and solvent-free home restoration products. Inspired by her Swedish heritage, she advocates for sustainable, plant-based materials like linseed oil paint and pine tar.
Gina Ciganik – CEO, Habitable
Gina Ciganik, CEO of Habitable, has been instrumental in growing and scaling the organization’s vision since assuming the role in 2016.
Recognized nationally for her leadership in transforming human and environmental health, Gina’s strategic partnerships and innovative practices have reshaped housing standards across the affordable housing sector. With a proven track record of creating healthier spaces–including the groundbreaking 90-unit apartment building, The Rose–Gina’s leadership drives Habitable’s mission forward. She sees herself as a “dot-connector” and translator who amplifies the organization’s impact, fostering holistic solutions for planetary health. Determined, curious, and joyful, Gina is committed to creating healthier environments for communities worldwide.
10/21 WEEK 7: IMPLEMENTING BIO-BASED AND EARTHEN ARCHITECTURE & STRUCTURES
Anthony Dente, P.E., LEED AP – CEO, Verdant Structural Engineers
Anthony Dente, PE, LEED AP, is a licensed engineer across the US, CEO at both Verdant Structural Engineers (VSE) and Verdant Building Products (VBP), and is the vice president of the Cob Research Institute (CRI). With VBP, he is leading the deployment of their carbon-storing, straw-insulated wall panels, developed under the EPA SBIR grant program. VSE assists with permit acquisition as well as product, research, and code development for low-carbon structural solutions. He was the lead engineer for the Cob (Monolithic Adobe) Construction Appendix in the International Residential Code, as well as the Hemp-Lime (Hempcrete) Appendix, both the first of their kind in the US. Anthony is the chair of the structural sub-committee of the TMS Earthen Modular Masonry Standard Committee developing the much-needed contemporary adobe and CEB building code. Anthony recently authored Essential Cob Construction, A Guide to Design, Engineering, and Building with New Society Publishers.
David Arkin, AIA – Arkin Tilt Architects
David Arkin, AIA is a principal of Arkin Tilt Architects, a northern California firm founded in 1997 with a focus on the intersection of design and ecology, including straw-bale and rammed earth, renewable energy systems, greywater, and reused & biobased materials. For ten years, David served as Director of the California Straw Building Association (CASBA), advocating for natural building systems in the building codes, and publishing ‘Straw Bale Building Details, An Illustrated Guide for Design and Construction’. He served as co-Chair of the AIA’s 2030 Commitment Working Group; in 2025 he created and co-hosted the monthly ‘Grow ‘n’ Tell’ webinar for the Bio-Based Materials Collective (BBMC). A native of Wisconsin, David studied architecture at the University of Minnesota and UC Berkeley.
K. Ben Loescher, AIA – Founding Principal, Terrain
Ben Loescher, AIA, is an NCARB Certified Architect and a LEED Accredited Professional. He is the Founding Principal of Terrain (formerly LMA), where he provides leadership and guidance and has acted as Project Director on multiple projects, including Skydance Media, Warner Brothers, the Beats by Dre Headquarters, Illumination Entertainment, and Neuehouse.
Ben is an expert in the adaptive reuse of existing structures. He holds a Master of Architecture degree from the University of Michigan, a Master of Arts in Architectural History and Theory from The Architectural Association in London, a Bachelor of Environmental Design from Miami University, as well as a Certificate in Adobe Construction from Northern New Mexico College.
Ben founded Adobeisnotsoftware – the earthen education and advocacy arm of Terrain. He is the former President of The Earthbuilders Guild, Adobe in Action, and The Friends of Pioneertown, and acts as a Program Manager for the Center for Land Use Interpretation.
Wilfredo Paz Bermudez, P.E. –
NEED BIO
10/28 WEEK 8: CLOSING – LEARNING FROM EUROPE
2nd Speaker TBC
3rd Speaker TBC
