Coming this fall: Commercial and industrial architects will be able to more easily specify hemp-lime “hempcrete” in large-scale projects after the US Hemp Building Association board voted in July to support the release of a commercial guide specification.
A May poll of USHBA’s Corporate Members identified the release of a commercial guide spec as a priority for 2023, the board said.
“US architects who want to design the big multi-story hemp-lime projects that are popping up in Europe have been frustrated because there’s no easy way to spec these materials in US projects, without creating an entire guide spec from scratch,” said Ray Kaderli, USHBA president. “We want to make it easier for architects to include hemp-lime in their materials selection.”Architects use guide specs when incorporating a material into a project’s construction documents. Even though hemp-lime technology has been used in Europe for 30 years, it is a new material in the US, gaining acceptance after the 2018 Farm Bill legalized the growing of industrial hemp.
Because hemp-lime is not sold by a single manufacturer, the trade association board voted to remove barriers for all manufacturers by supporting an accessible guide spec for all users.
Specs for hemp-lime wall infill material will include technical data, ASTM standards (as developed), performance features and product attributes. They will be updated as more US standards are developed.
In 2022, USHBA removed barriers for residential home projects by winning approval for hemp-lime in US building codes in the upcoming 2024 International Residential Code.
The guide specs will be prepared by Fairfield, CT-based ARCAT, and written by fellows from the Construction Specifications Institute. The specs will follow the CSI 3-part and the Canadian CSC formats for building and construction professionals. The specs will be free to view and download.
Commercial and industrial architects are the ultimate decision-makers who can drive the supply-chain demand on an industrial scale for hemp and other natural building materials.
Some large-scale architects are already specifying hemp-lime for insulation on big projects, most notably, the Urban Sequoia, a carbon sequestering hempcrete insulated high-rise rolled out in 2021 at COP 26 and again in 2022 at COP 27 by SOM (Skidmore Owings & Merrill).
“We understand that architects want to design better, more sustainable, and healthier buildings, AND the market is demanding it,” Kaderli said. “Our trade association needs to help architects meet these demands.”
The guide specs should be available in the fall.