Could 'printing' new houses solve the affordability crisis?

A 3D-printed house in Tabasco, Mexico. Photo: Joshua Perez/New Story
A 3D-printed house in Tabasco, Mexico. Photo: Joshua Perez/New Story

As the cost of buying or renting a property in regional Australia reaches unprecedented heights, it's clear that building more housing stock may be part of the solution.

But with construction prices already rising prior to the pandemic, and swelling further still due to global supply shortages of critical materials, experts say it's time Australia seriously reconsiders its approach to building new homes.

As part of the fifth instalment in Australian Community Media's six-week Regional Housing Solutions series, we investigate the way in which two construction innovations, prefabricated manufacturing and 3D printing, could drive down house prices.

Missed earlier stories in the series? Catch up here:

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The current state of play

According to the Australian Bureau of Statistics, the cost of building a house, townhouse or apartment increased by 59.5 per cent, 70.9 per cent and 49.1 per cent respectively in the 15 years to 2019.

The average cost to build a house was $320,238 in the 2018-19 financial year.

But supply shortages since the pandemic has started have pushed prices higher, and blown out construction times.

A shortage of materials like timber, steel and electrical fittings were all contributing to the blown out construction time, which in turn led to increased costs.

Good for jobs, climate and affordability: Why we need to shake off our negative perception of prefabricated housing

University of Melbourne Professor Alan Pert, Deputy Dean of the Faculty of Architecture, Building and Planning, said that the construction industry in Australia was facing a number of pressure points, only one of which was affordability.

"I think issues of affordability are complex, the construction side is one part of it but I do think we're at a fascinating conjuncture where it's a perfect storm," he said.

"Issues of climate change and decarbonising the construction industry is increasing pressure on construction companies and even looking at material supply there's a lot of focus on issues of import and export."

These pressures all created a strong case for greater adoption of prefabricated construction in Australia.

Prefabricated housing, manufactured en masse in a factory setting and then transporting to site, created an economy of scale while also leading to greater environmental outcomes.

"[It provides] certainty around time with construction ... Things to do with [removing] waste material, a lot of stuff that happens onsite," he said.

Part of this scaling up of house manufacturing would include establishing local material supplies, negating the impact of global supply shortages, and also reducing the construction sector's carbon footprint.

Overseas, prefabricated manufacturers including Ikea-owned BoKlok have partnered with local councils to supply housing.

Professor Pert said that in Australia around one third of new schools were constructed using the prefabricated method, with the key issue preventing wider acceptance of it in the residential sector being the lack of a guaranteed pipeline of projects.

"There's already an industry developing there because there's a pipeline [of school projects]," he said.

In this sense, Australia was lagging behind its international counterparts, although the Victorian government's Homes Victoria project was a sign that this was changing.

Constructing house components offsite reduces material waste and labour costs. Photo: Shutterstock

Constructing house components offsite reduces material waste and labour costs. Photo: Shutterstock

Along with reducing material wastage, prefabricated housing, or what the construction industry terms Design for Manufacture and Assembly (DFMA), helps reduce labour costs according to Professor Peter Wong, Associate Dean of Construction Management in the School of Property, Construction and Project Management at RMIT.

On large apartment projects, where prefabricated construction is typically employed, the time savings can be as much as 20 per cent, he said.

"On foreign projects it's about 15-20 per cent of the efficiency. For a high rise of 20 storeys, the normal turnaround would be around 18-24 months, for DFMA it's reduced by 10-20 per cent to as low as 12 months," he said.

Some buildings in Australia, in particular in Melbourne and Sydney, were already making use of DFMA, though it was yet to take off in the regions.

Professor Wong said that the model had the greatest potential in high-rise contexts, but there was nothing to stop the process being used for single dwellings.

Professor Pert said he could envision a strong market for prefabricated housing kits from owner builders based in the regions.

Both Professor Wong and Professor Pert said that one of the key barriers to widespread adoption in the residential sector would be casting aside negative perceptions of the term "prefabricated".

"I think part of the problem with prefab or modular is public perception," Professor Pert said.

"[There's a] huge misunderstanding that happened in response to post-war housing, things like public housing towers that used prefab, people associate the construction method with that," he said.

Other challenges would include re-training the workforce, including builders and architects, to adapt to the new method of construction, Professor Pert said.

Like making a cake: How 3D printing can make building faster and better for the planet

Huge production lines of prefabricated houses might well be part of Australia's housing future, but another option being explored by researchers would see a more localised solution in play.

3D printing of houses could allow for fast-paced construction of single dwellings onsite using recycled materials, according to Associate Professor Sandra Loschke, from the University of Sydney's School of Architecture, Design and Planning.

In simple terms, 3D printing is the process in which a 3D object is created from a digital design by adding layer upon layer of material on top of one another.

Professor Loschke likened 3D printing to making a cake.

"I like to say it's like a cake. You can change all of the properties as it is made, so it can be stronger and darker on the edges, for example" she said.

She has been working on a project backed by Forest and Wood Products Australia with colleague Gwenaelle Proust to turn timber and plastic waste into building products.

"Most of the forest products end up in landfill... Only 15 per cent make it into the construction industry," she said.

"In construction we tend to have big elements - timber beams you need a long tree and a lot of it goes to waste. 3D printing works on a micro scale so we can recycle pretty much anything," she explained.

Professor Loschke and Professor Proust have produced a wood-plastic composite, called 'Microtimber', that resembles natural wood, including a timber panel that resembles natural timber.

3D printing could be used to produce material components of a house but the technology could also be scaled to print an entire home, according to Associate Professor Loschke.

Two of the 3D printed houses in Tabasco, Mexico. Photo: Joshua Perez/New Story

Two of the 3D printed houses in Tabasco, Mexico. Photo: Joshua Perez/New Story

She pointed to a 3D housing project in rural Tabasco, Mexico run by charity New Story in partnership with US builder icon, as an example of the potential the technology could have in regional Australia.

Two affordable houses there were constructed within the space of 24 hours, a far cry from the six months or longer it would take to construct a home in Australia.

"Basically what they did is put a large printer in a container and brought it to the site."

Other than no longer having to source new organic materials, 3D printing offered cost savings in the reduced amount of time and labour needed for each project.

"The advantage is they can be built in situ - so you don't have to fabricate and then transport, store and transport again, all of this is cut out," she said.

According to Professor Loschke, 3D house printing offered the potential for a project to be managed remotely with only a single person onsite.

In regional areas, 3D printing could be used to build with whatever materials were locally available.

"You could use timber materials or you could use something else," she said.

While Australians may need to adjust their expectations about house sizes in a 3D-printed world, it was possible to live "in very conventional ways" in printed homes.

"The limits and opportunities are with technology," Professor Loschke said.

For example, houses would no longer need to conform to traditional shapes with 3D printing, with buildings likely to take on more organic shapes.

"You could give someone a pitched roof if they really wanted but usually in construction there's a logic and much of it comes from the material and the construction technique," she said.

This story Could 'printing' new houses solve the affordability crisis? first appeared on Newcastle Herald.