OCTOBER 14, 6:00 - 8:00 PM

The New Building Material 

Hemp is utilized as a non-toxic, sustainable building material. It is fast-growing, and requires low temperatures to process; hemp-lime buildings are carbon-neutral.  Hemp improves energy efficiency of buildings and replaces synthetic insulation and plastic wrapping.  Life-long hemp buildings are free of common indoor allergens and help keep inhabitants healthy.

Hemp provides an environmentally sustainable solution for potentially thousands of products including building materials, car parts, plastics, paper, textiles and ethanol.

Hemp fibres are extremely strong and durable and have been shown to be used in replacement of wood for many jobs including creating very durable and breathable homes.

The first example of the use of hempcrete was in 1986 in France with the renovation of the Maison de la Turque in Nogent-sur-Seine by the innovator Charles Rasetti.

In the UK hemp lime was first used in 2000 for the construction of two test dwellings in Haverhill.

Designed by Modece Architects,
who pioneered hemp's use in UK construction, the hemp houses were monitored in comparison with other standard dwellings by BRE. Completed in 2009, The Renewable House is one of the most technologically advanced made from hemp-based materials.

The first US home made of hemp-based materials was completed in August 2010 in Asheville, North Carolina.

A panellized system of hemp-lime panels for use in building construction is currently under test in a European Union funded research collaboration lead by the University of Bath. The panels are being designed to assure high quality construction, rapid on-site erection, optimal hygrothermal performance from day one and energy and resource efficient buildings. The 36-month-long work programme aims to refine product and manufacturing protocols, produce data for certification and marketing, warranty, insurance cover and availability of finance. It also includes the development of markets in Britain, France and Spain.

Hemp is used as an internal plaster and is a mixture of hemp hurd (shive) mixed with larger proportions of a lime based binder. Hemp plaster has insulative qualities.


Carpool when possible.


October 3 - Indoor Air Quality Seminar, Redwood Credit Union, Santa Rosa, CA

November 12 - Year-end Gala, the French Garden Restaurant, Sebastopol, CA

December - Date TBC. 
The Latest Lighting Technologies / Energy Plus, Santa Rosa, CA

The New Building Material

Wednesday, October 14, 6:00pm - 8:00pm
$20 General Admission 
$15 REC Members (members code will be sent via email) 

AICP CM credit pending.

Event Location / Host: 
The Seed Bank
199 Petaluma Blvd. North
Petaluma, CA 94952
Phone (707) 773-1336 

In appreciation to our partnering organization:

California Straw Building Association

The presentation examines the basic ingredients used to make hempcrete and covers the material properties of hempcrete. Chris will cover the appropriate uses of hempcrete within a building, including wall, roof and floor insulation, as well as use in cordwood construction and as window insulation and trim, and show various techniques for shuttering/forming hempcrete. 

The embodied energy and carbon of the material as well as the costs are covered in detail, as are mixing techniques. The presentation also shows photos of finished hempcrete buildings in Ontario, Canada.


Executive Director 
The Endeavour Centre
Ontario, Canada

Chris Magwood
Chris Magwood is obsessed with making the most energy efficient, beautiful and inspiring buildings without wrecking the whole darn planet in the attempt. He co-founded Camel's Back Construction, and over eight years helped to design and/or build around 30 homes and a few commercial buildings, mostly with straw bales and often with renewable energy systems.
During this time, he co-authored three books on straw bale construction: Straw Bale Building, More Straw Bale Building and Straw Bale Details. He was also the editor of The Last Straw Journal, an international quarterly of straw bale and natural building. He has contributed articles to numerous publications on topics related to sustainable building. His forthcoming book, Making Better Buildings, was published in 2014. His new books, Essential Prefabricated Straw Bale Construction and Essential Hempcrete will be published in 2016.
Chris is currently the executive director of The Endeavour Centre, a not-for-profit sustainable building school in Peterborough, Ontario. The school runs three full-time, certificate programs: Sustainable New Construction, Sustainable Renovations and Sustainable Design and hosts many workshops.

Sustainable properties / Use in construction

Details from the website of - a future project in Bellingham, WA. 

Hemp is an efficiently renewable annual crop, growing in about 90 to 120 days to yield 4-6 tons of carbon sequestering bio-mass per acre.  The carbon that is locked up in the plant, offsets that which is released by heating the lime, the other main ingredient used to make hempcrete. 

Lime, like cement, is calcined to drive off Co2.  Then, as a powder, it can be reconstituted, cast, and molded.  It sets up by taking back the molecules that were driven off in the heating. Cement is heated high enough to make a solid set that will not deteriorate under water.  Lime, on the other hand is fired to a temperature that encourages a slower set, curing over a long period of time-50-100 years!   As it cures, the lime continues to pull carbon from the atmosphere in a process of calcification.

See the first permitted hemp construction in California. To view images go to:

Linda Delair, representing Hempstead Project Heart will be giving a presentation on the use of hemp in this residential construction project.

Registration button

We partner with other like-minded organizations to deliver quality sustainable education. We hope to influence building professionals in the most positive way, so they may contribute to a healthier, vibrant, sustainable local community. Join the chapter today.

U.S. Green Building Council
Redwood Empire Chapter
2360 Mendocino Ave.
Suite A2-156, Santa Rosa, CA 95403-3154