Australia’s housing crisis has reached critical levels. Since 2019, residential housing prices have risen by 38% while capital city rents have increased by 15%. Construction times have also blown out, with stand alone houses now taking 12.7 months to complete compared to 9 months fifteen years ago. The situation is compounded by a serious shortage of skilled labour, with 27,500 vacant construction jobs in the first quarter of 2024. While various factors contribute to the crisis – from inflation pushing up construction costs to population growth increasing housing demand – it’s a complex problem that can’t be solved overnight. What’s certain is that relief is needed as soon as possible, and 3D printed housing may have a significant role to play.
Texas innovation with 3D printed suburb
I think I first saw a 3D printed building on a series of The Block. The concept has definitely moved beyond the experimental stage with successful implementations worldwide. One such example that I read about recently was the Wolf Ranch development in Georgetown, Texas. It’s touted as the world’s first and largest 3D printed neighbourhood. This ground-breaking 100 home community showcases the technology’s viability at scale. The homes range from 139 square metres to 195 square metres, offering eight different floor plans with three to four bedrooms and two to three bathrooms. Priced between $475,000 and $570,000 USD (about $728,000 to $874,000 AUD), each house comes equipped with eco-friendly features including solar panels, smart thermostats, Ring Video doorbells, and Wi-Fi operated locks.
The construction process, handled by ICON’s massive Vulcan printer, can see all internal and external walls completed in about 10 days. Traditional construction crews are responsible for the foundation and the metal roofs.
Dubbo’s pioneering 3D house project
Australia is following Texas’ lead with the New South Wales government launching a groundbreaking initiative in Dubbo. It will be the country’s first 3D-printed social housing project and is being delivered through a partnership between Aboriginal Sustainable Homes (ASH) and 3D-printing specialist Contour3D. The same company that built The Block printed house I saw. This development will see two modern two-bedroom duplexes built for Aboriginal social housing tenants. The project is already ahead of schedule with the duplexes expected to be completed in 16 weeks rather than the initially predicted 40 weeks.
Contour3D’s printer named OPUS is Australian designed, engineered, and manufactured. Standing at 30m (L) x 12.5m (W) x 3.9m (H), it also has extension capabilities, can be easily assembled without the use of cranes, and can be operated remotely via tablet. It delivers millimetre precision with each layer, and features self-correction capabilities.
How 3D print construction differs from traditional homes
3D printed homes differ significantly from traditional construction in several key areas.
Wall structure
Instead of timber frames with cavities for insulation and services, 3D printed homes are made from special concrete and can be constructed in a few ways. They either have solid concrete walls without cavities, more advanced designs with purposely printed cavities or a combination of the two with two separate walls put up with a gap between them. These gaps can be used to run services, and can be filled with insulating materials reducing U-value by up to 60%. U-values measure how easily heat passes through, so the lower it is, the better the insulation. Contourcrete, the material being used at Dubbo, is made from 40% recycled materials and has a high thermal rating creating a more energy efficient home.
Waterproofing and sealing
Traditional homes use standard waterproofing membranes and flashings. These are crucial in areas prone to water exposure, such as roofs, balconies, bathrooms, and the joints of windows and doors. In 3D printed homes, specific attention has to be paid to waterproofing and sealing due to the unique characteristics of the construction process and materials used. For instance, special flashing is required around curved and corrugated features which are a common element of 3D printed homes. And unlike traditional construction, where waterproofing can be integrated during the build, 3D printed structures often require additional waterproofing after printing. This can include applying sealants over the printed surfaces to enhance water resistance and protect against environmental elements.
Windows and doors also need particular care because the integration with printed walls can be less straightforward than in traditional construction. 3D printing involves layering material, which can lead to joints between sections that might not be perfectly aligned or sealed. Specific flashing and sealing techniques must be employed around these openings to ensure they are watertight.
Service integration
Services like electrical wiring, plumbing, and HVAC systems are integrated into the build process for traditional homes. But 3D printed homes require pre-planned conduits for electrical wiring, special channels for plumbing, and additional consideration for service installation points. It’s very difficult to make modifications post-construction so services have to be well thought out.
Maintenance
As you can imagine, maintenance is also of the utmost importance and repairs need to be kept on top of to avoid major structural damage. It’s recommended that annual professional inspections be undertaken, regular cleaning of exterior walls with mild soap and water is maintained, and periodic painting is undertaken for both protection and aesthetics.
Benefits and performance of 3D printed houses
The efficiency of 3D printed construction is remarkable when compared to traditional building methods. While residential homes can take on average over 12 months to build, 3D printed homes can have their basic wall structures completed in just 24-48 hours, with house shells finished in 2-3 weeks. The precision of 3D printing technology means material waste is reduced, while incorporating 40% recycled content in Contourcrete (the material used in the Dubbo project) enhances its environmental credentials.
Contourcrete also achieves 45MPa strength and requires minimal reinforcement compared to traditional concrete. This strength rating is comparable to high-strength commercial grade concrete typically used in large building foundations, heavy traffic roads, and supporting beams.
Environmental impact
The environmental benefits of 3D printed homes are substantial. The technology delivers a 30-40% reduction in carbon emissions compared to traditional construction methods. The use of locally produced materials reduces transportation emissions, and the enhanced thermal properties of the printed structures contribute to lower energy consumption throughout the building’s lifetime.
Economic advantages
The financial benefits are also compelling with production costs reduced by 20-45%. Labour costs are minimised as the process only requires 2-3 people to maintain the printer, compared to large traditional construction crews. Reduced construction timeline means faster return on investment. And there’s less wastage of material as the printers are precise.
What does this mean for traditional tradies?
3D printed homes seem like an ideal solution to the skilled trade shortage gripping Australia. But will trades become extinct? Not quite. Electricians, plumbers, and HVAC specialists will still be needed, as will finishing trades like painters, gyprockers, cabinet makers, and flooring specialists. Excavators, roofing specialists, and window and door installers will also be needed.
On the face of it, it would appear that carpenters are most in danger of no longer being needed. But even with 3D printed homes, carpenters have a role to play – in cabinet and furniture making, interior trim work, and custom finishes. Many 3D printed homes will also still require interior walls to be framed and finished with gyprock.
If anything, new roles will emerge. There’ll be a need for 3D printer operators, technicians, engineers, digital design specialists, and material technologists. Rather than eliminating jobs, 3D printing will transform how current trades operate. Traditional tradies will need to adapt to working alongside new technology. Workers may need to develop additional digital skills. The technology supplements rather than replaces skilled trades, with 3D printing handling the basic structure while traditional trades remain essential for finishing the building.
Future outlook
While 3D printing technology shows immense promise, it faces some current limitations including restricted material options and the need for specialised training. However durability testing indicates that a well-balanced, 3D printed concrete building should last between 50 and 300 years. While 3D printed houses won’t be suitable for every project, they could well be an answer to the lack of affordable housing facing many countries. Dubai plans to have a quarter of all new buildings 3D printed by 2030 demonstrating a commitment to sustainable urban planning. The success of projects in Texas and Dubbo among others shows the viability of this technology in delivering high-quality, affordable housing while maintaining construction standards and sustainability goals.
References
https://insidelocalgovernment.com.au/3d-printed-home-build-underway-in-dubbo/