3D-printed houses in Australia: a viable option?

As state and federal governments scramble to find solutions for how to best manage the next few years of the pandemic, discussions about the building of for-purpose quarantine centres seem to be getting little traction. Some premiers, such as Western Australia’s Mark McGowan, believe it will take years to build new facilities, while Prime Minister Scott Morrison has expressed hope that a facility in Mickleham, Victoria, could be ready before the end of the year (at the price tag of $200 million for a 500-bed centre).

But building these bases doesn’t have to take years or cost hundreds of millions: in fact, as one Melbourne-based startup points out, a one-bedroom, one-bathroom unit can be built in as little as 18 hours and for $7,000 – provided we use 3D printing technology to do it.

Ahmed Mahil, the CEO and co-founder of Luyten, a local specialist in manufacturing 3D printers and concrete printing technology, says his company has developed a technique that could see quarantine facilities cost 80% less when compared to traditional construction, and 55% less when compared to more traditional prefabricated solutions. He estimates that a 3D-printed, 500-bed quarantine hub would cost $80 million, as opposed to $200 million.

So if this technology already exists and we know it works, why aren’t we using it more?

A one-bedroom, one-bathroom unit can be built in as little as 18 hours and for $7,000 – provided we use 3D printing technology to do it.

In Australia, housing unaffordability has become so endemic that the House of Representatives Standing Committee on Tax and Revenue has recently launched an inquiry into the issue, arguing that “home ownership, one of the building blocks of Australian society, has been falling for the last 30 years”.

Yet, according to Mahil, we could be building three-bedroom, two-bathroom houses in as little as a week at a fraction of the cost currently facing Australians.

What’s the hold-up?

What is 3D printing, and how does it work?

It may seem like science fiction, but the ability to print solids has been around since the early 1980s, when Charles Hull, currently the co-founder and chief technology officer of 3D Systems, invented stereolithography (3D printing)

Since then, 3D printing technology has increasingly been used for mass customisation and the production of many types of open-source designs in agriculture, healthcare, car, locomotive and aviation industries. Its potential seems unlimited.

When it comes to houses, we are already seeing projects such as those led by US firms Palari Homes and Mighty Buildings selling out as eager consumers snap up homes that are being built in as little as 24 hours. In 2016, Chinese construction firm Huashang Tengda 3D-printed an entire two-storey house in 45 days.

And while the details may vary according to industry, size, material and quantity, the principle of 3D printing is basically the same: it is a manufacturing process in which material is laid down, layer by layer, to form a three-dimensional object based on the instructions of a computer program.

M. Hank Haeusler, an associate professor at the University of New South Wales, is an expert in architecture and computational design and has for years been preparing his students to think about designing buildings in a different way – one that marries software, design, efficiency and a clean environmental footprint.

“3D printing is no longer a revolutionary concept – we are doing it as we speak,” Haeusler says. “Imagine a hot glue gun that can smear some glue on a piece of paper, which then moves around and builds up layer after layer until you get a 3D object. Not only is it very easy, but you can make these prints as big or small as you want.”

Haeusler says that for housing, “you would normally use structurally sound material like concrete, clay or cob so that the house can withstand gravity, environmental and mechanical forces”.

“With specifically designed software, you choose the house you want, select all the regulations and variables that go into that, and the printer will then execute what it reads in a 3D way.”

The quantity and type of material needed are also subject to geographic locations and governmental (including local council) regulations: with Australia being such a large country, different areas face different challenges, be it earthquakes, climate, floods or fires.

But before you even get to the material, you need software that can speak to the computer, says Mahil.

“It’s all about how you design the program and what you put in it – the machine will read that and print accordingly,” he says. “With specifically designed software, you choose the house you want, select all the regulations and variables that go into that, and the printer will then execute what it reads in a 3D way.”

Luyten’s 3D printer is able to adjust its settings to suit the velocity, quantity and type of material being fed into it. Mahil says it is the first and only such machine made in Australia – a mobile robotic transformer that is capable of printing a three-bedroom, two-bathroom house in a week.

What are the challenges?

The main challenge to widespread 3D adoption, says Haeusler, is having architects who are able to design buildings with construction instructions that can be understood by a machine, instead of instructions that can only be understood by humans.

As it stands, most architects still document their designs in software packages such as BIM (Building Information Modelling) to ultimately produce a PDF to be printed onto paper — readable by humans. “If they keep designing in this way, we will never be able to unlock the full potential of 3D printing, as a 3D printer cannot directly read a PDF but needs machine code,” Haeusler points out.

“This is why we teach computer programming for architecture to my undergraduate students: they need to understand what a machine needs in order to fabricate something, and what variables exist in a building that could define a design outcome, and bring all of that together in a program. Essentially our students design the program and the building is the resulting product.”

Computers are much better at maths than human beings, so designing a program that includes all sorts of variables and can recalculate building dimensions, materials and so on according to different scenarios will be an invaluable skill.

“This will also enable customisation and more complex design: if you want to add something specific, you can explain your preferences in numbers to the computer and have it account for that,” Haeusler says. “Traditionally, if you wanted to do that you’d have to get an architect to redraft your house plan.”

Where computers fall short is being able to read and understand beauty, he says.

“Aesthetics are very important to us humans. So you still need to look over the machine design and assist with the aesthetic preference.”

How much does it cost?

With average house prices in Australia’s capital cities climbing at historic rates (Melbourne’s median house price has just reached a record $1m, while Sydney is now closing in on $1.5m), home buyers are keen to save money wherever they can.

The obvious place to start is to build in a way that reduces wastage, and therefore cost, says Mahil.

“If you have a precision machine calculating how much material you need, like ours does, you will be paying $12,000 for the walls of a 250 square metre house instead of the $60,000 to $80,000 with traditional methods,” he says.

Waste such as rubble and concrete made up nearly 30% of the total waste generated or imported by the Australian economy.

Labour in Australia is also expensive, so cutting out some of the positions involved in construction (superintendent, construction manager, fabricator, some designers, stonemasons, engineers, etc) will save people thousands. Glaziers, plumbers, electricians and fitters, however, are still required, but their jobs will be easier. “The computer can calculate exactly where the best place to put an electrical socket is, for example, so the electrician won’t have to spend as long assessing the structure,” Mahil points out.

“Using our recipe, building a section of a wall that’s 2.5m long, 1m high and about 0.5m wide will cost about $160, compared to the $1,300 to $1,800 you would pay for the traditional brick and mortar method,” he says.

And while this may sound like the end of the building and construction labour force, Mahil is quick to point out that widespread adoption of 3D machines in the industry doesn’t spell the end of jobs – it just redirects skills.

“We are aiming to make construction work more skilled; knowing how to 3D print is a transferable skill, and if you can 3D print concrete, you can one day 3D print rockets,” Mahil says.

What’s the environmental impact?

Australia’s construction and building sector is one of the biggest emitters of greenhouse gases per capita in the world. According to the Australian Bureau of Statistics, in 2016-17 the Australian construction industry generated 20.4 megatons of solid waste in just one year, the majority of which was masonry waste such as rubble and concrete. This made up nearly 30%of the total waste generated or imported by the Australian economy during that time.

The World Green Building Council says that building and construction are responsible for 39% of all carbon emissions in the world, with operational emissions (from energy used to heat, cool and light buildings) accounting for 28%.

Both Haeusler and Mahil say this doesn’t have to be the case: if we combine machinery with computers, we can calculate exactly how much material is needed and avoid waste, and specifically waste generated from reinforcing concrete structures.

“Forty-one per cent of construction waste is timber used to reinforce concrete structures; timber that can only be used a maximum of five times – and even that’s pushing it,” Mahil says.

“3D printing doesn’t need support material, as it uses only the material it prints, and by using 3D printing in building and housing, we can cut construction waste by 60%, production time by 70% and labour costs by 80%.”

“Architecture, design and construction are the highest consumers of natural resources we have on the planet,” says Haeusler. “We don’t have unlimited iron and sand to use.

“If we want to continue building the same way as we do now, we’ll simply run out of materials.”