“Why isn’t everyone using it?” Bushfire victims rebuild home with hemp


Hemp grown for industrial use around the world is a strain of the cannabis plant with significantly lower THC. Picture credit: Pixabay

A couple who lost everything in February’s devastating Wooroloo bushfire is rebuilding with a twist – their new home will be made of hemp.

Pete Costigan and Alex Hopkins had only lived in their Gidgegannup home for five months when it was razed alongside 85 other houses when a devastating fire ripped across 26km of land north-east of Perth.

The couple’s new home will be the first in the area to use a product called hempcrete, which mixes hemp fibres with lime and water rendering it resistant to fire.

“It’s fireproof, termite proof, and when it’s built correctly it offers the best insulation you can get,” Ms Hopkins says.

“You’ll keep your bills down over time and it’s more environmentally friendly … why aren’t we all using it?”

While the project will require specialised builders and be a more difficult and expensive build compared to using traditional materials, the couple hope that the long-term energy savings from running an eco-friendly home will offset initial outlays.

Hempcrete homes, which are already used in other parts of the world, are touted to be more energy efficient as the material is a natural insulator that also absorbs water vapour.

A review study by University of Milan engineer Dr Carlo Ingrao found that hemp-based buildings are carbon-negative because hemp absorbs and stores carbon dioxide as it grows.

There are several other hempcrete homes in the South-West, with the first built in 2017.

Local council, the City of Swan, had never dealt with a housing application like Mr Costigan’s and Ms Hopkins.

Ms Hopkins says despite construction hemp containing barely any psychoactive THC, she still faces tongue-in-cheek comments from friends.

“Hemp’s known for its smoking qualities,” she says.

“Everyone says ‘hey, we can go in your house and get high’ … you have to put up with the joking part.”