Dismayed by the costs of home ownership in Australia, a West Australian couple is building their castle out of earth bags to escape the mortgage trap.

The unconventional technique involves building dome-shaped structures out of bags filled with earth and held together with barbed wire.

Kate and Scott Ryan-Taylor, from Kendenup in WA's Great Southern, made the decision to build with earth bags after realising the conventional path to home ownership was too costly.

"We'd be in debt up to our eyeballs until we're 70 or 80," Mrs Ryan-Taylor said.

"We want to be able to have a place we can afford.

"We don't want to be retiring and then have no time to enjoy this place."

The earth bag home will be Australia's first approved by council for residential purposes ( ABC Great Southern: Aaron Fernandes )

Dirt cheap build cost

The couple estimate their home will cost less than $40,000 to build, and have invited volunteers from across Australia to stay on their 27-acre property and help with the construction.

In exchange, volunteers learn firsthand how to build with earth bags.

"Within 10 years we should be pretty much debt free," Mr Ryan-Taylor said.

"We had to get a mortgage for the land of course, but other than that we don't owe any other money.

"The only way we can [live the life we want] is to build something that were not going to be paying off for 50 years.

"We'll be finished paying for this by the time it's built."

The Ryan-Taylors work with volunteers to build their home. ( ABC Great Southern: Aaron Fernandes )

What on earth is an earth bag?

Earth bags are a little-known building material favoured by alternative lifestyle seekers for their low cost and environmental sustainability.

After deciding against commonplace building methods, Mr and Mrs Ryan-Taylor realised they had a cost-free building material right beneath their feet.

The bags are filled with a combination of sand, clay and gravel and laid in rows like bricks to build the walls of the dome-shaped structure.

Bags are filled with a combination of sand, clay and gravel. ( ABC Great Southern: Aaron Fernandes )

"The easiest way to explain it is similar to rammed earth, but you're actually putting [the earth] inside the bag itself and [laying it] to form the wall," Mrs Ryan-Taylor said.

"You're filling up the equivalent of 40-kilogram feedbags and tamping it into shape on each layer.

"You put layers of barbed wire in between, which holds the two layers together … and slowly work your way up.

"From the bottom rows, we'll start moving in to create a dome shape.

"So the walls and the roof are essentially the same thing."

Dome home

Mr and Mrs Ryan-Taylor described their home as Australia's first earth-bag home to receive full council approval for residential purposes.

The couple purchased the original plans for their earth bag home from a US website, and then spent months studying building codes to ensure the original design met Australian standards.

"I found every little exception right down to the ways that the doors are facing," Mrs Ryan-Taylor said.

"We had to look at everything, from the energy efficiency to bushfire safety, an engineer to sign off on the foundations and structural integrity of the building, and a building surveyor to do a certified design compliance."

The first rows of the earth bag dome being built. ( ABC Great Southern: Aaron Fernandes )

The couple said they dealt with plenty of scepticism along the way.

"To get to that point, we actually had to educate nearly every single [authority] about earth-bags," Mrs Ryan-Taylor said.

"The exception being the engineer, who had dealt with similar types of buildings in the UK."

After two years and several compromises on the original design concept, Mr and Mrs Ryan-Taylor had met Australia building codes and received full council approval.

"We actually had to get an expert review to show that this would hold temperature and be energy efficient … even though it's been proven that [earth bag homes] stay 21-24 degrees all year round."

Plan for the future

The couple planned to continue construction on their home at a cracking pace, with more volunteers expected to arrive in Kendenup every Saturday for the next six weeks.

"I was managing to get one row of bags done every week or two," Mr Ryan-Taylor said.

"We're going to get one or even two done today alone."

Mrs Ryan-Taylor said in exchange for their time, volunteers learned how to cut through council red tape and saw how to build their own earth-bag home.

Volunteers have been invited from across Australia to help build the Ryan-Taylor's earth bag home. ( ABC Great Southern: Aaron Fernandes )

She said the technique offered a path to a debt-free future.

"We've spent a couple of years going through the red tape and process, but in the end we're going to have something that we love and its going be really different," she said.

"Down the track, we won't be working full-time, because we will be paid off.

"So we can be semi-retired, if not getting an income from this place.

"We're not going to be burnt out and never able to enjoy our land.