A home made of hempcrete –a mixture of lime, water and industrial hemp– is the most recent bit of brilliance I’ve found in my ongoing scan for creative housing ideas. Known by various trade names, including Hemcrete®, Isochanvreis, Canosmose, and Canobiote, the substance is durable, waterproof, fireproof, insect and rot resistant. Significantly, it is also Carbon Negative, meaning that it traps more CO2 than its production creates. Plus, it has an exceptionally high insulating capacity.
The Hempcrete House was built in Asheville, North Carolina by eco-friendly design and construction company Push Design for the former mayor of Asheville. (read more at the Asheville Citizen Times website). It’s an elegant soft contemporary (Check out this YouTube by Hemp Technologies,) but the material would adapt well to our Pueblo vernacular. Hempcrete is made by pouring a lime-water-hemp slurry into small containers which are then packed between forms. After drying, the 12″ thick walls are then covered with lime and stucco. The result could easily comply with Santa Fe’s Historical Building ordinance.
Hemp remains illegal to grow in the U.S. and expensive to import. Yet, unlike its controversial cousin, hemp would be impossible to abuse. As Push Design’s David Mosrie puts it, someone “would have to smoke the Master Bedroom [2500 pounds of hemp] to get high.”
I tapped Kim Shanahan, executive officer for the Santa Fe Home Builders Association and respected local Green Building expert, for his opinion. “Until we can get back to growing industrial hemp here in the U.S., I don’t see a practical application here in Santa Fe.” Shanahan did introduce me toFaswall, an amalgam of mineralized wood chips, concrete and fly ash that’s comparable in characteristics, though without the hemp composite’s carbon negative appeal. “Any re-use of waste products is a good thing,” said Shanahan. “Adobe is still our favorite indigenous product, followed quickly by locally, sustainably harvested wood.”
Until hemp growing is given a regulatory green light, its use is likely to be restricted. But its ability to adapt to traditional and modern building styles and superior ecological value make it a promising –if distant– Green building possibility for the Santa Fe home market.
**On Tuesday, March 1, 2001, Daniel Clavio and Robin Dorrell will teach a 3 hour class on Alternative Building Methods and Materials at the Santa Fe Community College. Learn about the energy efficiency and Green characteristics of straw bale, adobe, Insulated Concrete Forms (ICF), Pumice Crete, Aerated Autoclave Concrete and more. The course will touch on new insulation and advance framing techniques and briefly discuss other forms of alternative construction including rammed earth, straw/clay, cob, timber frame and Earth Ships. This economical course should be an excellent lay person’s introduction to the field. Thanks to the Santa Fe Creative Tourism Blog for bringing this to our attention.