Hempcrete homes and their benefits include being ‘natural’, they sound cool, like “hey dude you’re cool”. Why wouldn’t you have one?

We’ve done all of the hempcrete courses in Australia and researched it a lot.

We’ve built walls from it. It’s a great natural resource, it only takes 3 months to grow, and they can be insulative or provide thermal mass in theory.

As natural builders, we love building with any natural materials. We’ll build with anything, the more natural the better.

There are some materials that aren’t as close to natural as we’d like, however they’re better than fired brick, glass or concrete.

Here are the reasons why we’re not building with hempcrete just yet:

  • Hemp plantations aren’t fully up and running atm in Australia, the farmers aren’t up to speeds or have enough for us yet. We can’t buy direct from them and they don’t get back to you
  • If we want hemp we have to buy it through a sourcing agent, which is sourced from Europe. Why use an overseas material when we have local materials
  • The binder is also sourced from overseas and the sourcing company has patented the binder. So you have to buy the whole thing. We get it because we have straw bale panels now
  • The cost of hempcrete isn’t cheaper than straw, it’s a little more expensive, which coincidentally is about the same as an architecturally designed home
  • When we make the walls on site, we can’t guarantee the quality or the R rating (each person tamps it down differently)
  • The actual R rating or insulation value isn’t as good as straw
  • The thermal mass performance isn’t as good as say recycled/reclaimed brick, cob or rammed earth
  • If we were to do them, we’d make them in a way where we can guarantee the quality
  • Because we’re licensed builders and have warranty on our work, plus we like to give great quality
  • It uses a LOT of lime, we have lime in our external renders, but the whole wall is made up of lime, that’s a lot of carbon (it’s like concrete)
  • Having said that, it’s a really great marketable ‘natural’ material. It sequests away carbon. We are testing it parts of the house. But we’re not ready to release anything yet though
6m rammed earth wall. Cement content is 6% stabilised
We prefer to use them as thermal mass walls on the inside of the building to lock in and trap heat throughout the seasons. (Ensure the sun doesn’t hit the wall in summer)
This regulates the temperature and keeps the building cool in summer and cosy in winter.
Thermal mass allows heat to transfer in and out of it.
The thicker it is, the longer it takes to heat up and cool down (think ceramic cup)

Whereas insulative materials stop heat from transferring in and out of it (think doona)