Hemp houses low-impact

When Alexia Jankowski and her partner Ben Whitaker decided to build a low-impact house in the hills, they turned to hemp — and say they hope one day their "very alternative building product" will be seen as mainstream.

The Western Australian couple hand built the three-bedroom home on a five-acre bush block in Kronkup, 30 kilometres west of Albany.

They say hemp, a plant product, has been used in numerous countries as a building material for thousands of years but it is relatively uncommon in Australia.

Ms Jankowski, an environmental scientist, said their goal was to build a house that was as low impact on the environment as possible.

"[Hemp] is an amazing insulator, it's fireproof, termite-proof and it also absorbs water vapour, so you don't get mould or dampness building up in your house," she said.

"Over the life of a building, it actually gets stronger. It feels like it turns into stone."

The couple's home is also solar passive, with its windows, walls and floors designed to collect, store, reflect and distribute solar energy in the form of heat during winter months and deflect heat in summer.

Couple gets hands-on with build

Most of the couple's hemp came from leftovers at the Denmark DecoVillage community housing project.

The hemp was mixed with lime and water to form hempcrete blocks, which were then used to make the walls of the house.

Margaret River builder Brendan Kelly put down the slab and erected the timber frame, the hemp walls and the roof. Ms Jankowski and Mr Whitaker did the rest.

"When it was the middle of winter, camping in the cold and compacting sand for the fifth week in a row, we definitely questioned whether it was worth it," Ms Jankowski said.

"But standing here now, enjoying the views and seeing everything we designed and imagined coming to fruition, it was definitely worth it."

A budget-friendly choice

For a building constructed from natural materials, the hemp house is surprisingly minimalist and modern in design.

A polished concrete floor is adorned with rainbow stones, shells and even sperm whale teeth to add unique character.

The internal walls have been left as exposed hemp, featuring cross sections of marri tree limbs.

"People might think of hemp as a very alternative building product, but it doesn't have to be like that," Ms Jankowski said.

"It can be a budget-friendly choice to have a house that is really modern looking ... It's not just hippy."

Hemp to become 'cheaper'

Ms Jankowski said the total cost of the build was about $300,000, which put it in the ballpark of conventional building products like double brick.

However, she acknowledged they had reduced the cost by building much of the home themselves.

"If anyone is exploring the idea of using an alternative building product they should definitely look into it [hemp]," she said.

"There are a lot of builders exploring doing hemp in panels that can speed up the process and make the labour less intensive.

"Every year there's more people building hemp houses and I'm sure it will only get cheaper and more accessible."