Hemp: The natural way to build

Hempcrete is the hero material in this beach pad.

Hemp is the hero material in this NSW south coast beach house.

Dominique Hage had only recently wrapped up her Master of Architecture degree when she landed her first big solo project.

Her parents Caroline Alcorso and Ghassan Hage had so much faith in their daughter’s ability to create their idyllic holiday home so soon after graduating, that they bought a block of land in Currarong, a small coastal village in NSW, and gave her only one direction: make it sustainable.

“It was a leap of faith to trust me,” says Dominique. “Also, a lot of people in design don’t like working with people they know, but I look at it this way. ‘I already have a good understanding on how they live and the lifestyle they want’. I was out in front before I had even stepped foot on site.”

Caroline Alcorso and Ghassan Hage entrusted their newly-graduated daughter Dominique to build them a sustainable beach on the NSW south coast.

Dominique’s parents are keen ocean swimmers and love to go hiking, and their love of nature would also extend to their new holiday home. There are multiple ways to build an eco-friendly home, but Dominique had a clear vision that included working with hempcrete. Hempcrete is a bio-composite material that can be used in construction as an alternative to materials such as concrete and traditional insulation.  

The basis of hempcrete is hemp, the balsa wood-like core of a cannabis plant.

Although hemp masonry has recently become popular in the construction of homes with low environmental impact and good thermal performance, it has been used as a building material for at least 300 years in Japan.

“I did comparisons with newer technologies and looked at the pros and cons. We landed on hempcrete at a time when it was fairly new to being manufactured in Australia,” says Dominique. “The breathability of the material was a massive drawcard for us. A lot of houses in Australia that are near a beach have damp issues, so to have something that could prevent mould was big. We couldn’t go past that.”

The concrete floor was created using grey ash waste from local factories and local white pebble aggregate.

There are second life interior doors, as well as basins, sinks, and appliances. The kitchen countertop has been made from a local tree which was cut down by the council.

“We also used grey water reticulation, rainwater and solar to make this house run on very little resources.”

As part of their eco-commitment. Caroline and Ghassan did not want a large house. Often Dominique will encounter new homeowners who want to build the biggest house afforded to them on their lot, but her parents wanted something pared back and respectful on their 400sq m block of land.

Hemp was also used to build the walls in the bedrooms.

“Normally as an architect you are pursuing the maximum floor space and mum was like, ‘no, I don’t want anything too crazy’. My parents also didn’t want something out of character in the area … anything that would stand out and look ‘boujee’ or contemporary in a small town.

“They wanted to maintain the Aussie beach house narrative but be innovative in other ways.”

That innovation came in passive design principles, from the window orientation to the thermal mass between the walls to moderate the temperature, right down to the L-shape of the home, which is designed to block the hot sun in the morning and filter through warm golden light in the afternoon.

The L-shaped home filters out the hot sun.

The build was completed almost two years ago and Dominique and her family have spent quite a bit of time in their beloved holiday home since.

“I love coming to stay. I have evolved as a designer but I see certain things with fresh eyes every time. I love what has stood the test of time, like the simple tile design in the bathrooms or seeing the raw brass tapware evolve over time. It’s beautiful. I’m looking forward to lots more family events there.”

Simple and stylish touches can be found throughout the home.

Easy to grow and process, hemp has a number of uses in building.

As hempcrete is made from a natural waste material, its entire life cycle as a building product is environmentally friendly.

Hemp weed construction

Any waste on site can be re-used in the next mix.

Hemp blocks

Hempcrete can help stabilise moisture levels in a building to avoid mould growth, making it a smart material to use when building near the beach.

Hemp homes are mould no-go zone