A spider-shaped construction robot named Charlotte is being developed in Sydney to 3D print a full-size house in roughly a day. Developers say the machine can autonomously form structural walls for about a 2,150-square-foot home using locally sourced materials.
Instead of cement and bricks delivered by truck, Charlotte compacts sand, soil, and clean waste into layered walls on-site. Researchers argue that this single-machine approach removes long supply chains and many high-carbon steps.
Charlotte, the construction robot
Charlotte is a mobile, legged system that pairs robotics with additive manufacturing, building objects layer by layer with a printer.
The prototype shown in Sydney is not a finished product, but its architecture offers a clear view of where construction automation is heading.
The work was led by Clyde Webster, founding director at Crest Robotics in Sydney. His work centers on agile field robots for construction tasks that are hard, repetitive, or risky. Momentum comes from the housing crunch and a push to cut carbon.
“The building materials that we use today – even a simple brick has so many processes involved and some of them very – very carbon-intensive,” said Dr. Jan Golembiewski, co-founder of Earthbuilt Technology.
From soil to structure
Crest describes an undercarriage-mounted system that gathers sand, earth, and crushed brick, binds the mix in textiles, and then compacts it into successive layers.
At the core is extrusion – pushing a material through a nozzle to form layers. That lets a robot produce continuous courses without mortar joints, guided by digital plans.
“It will work at the speed of over 100 bricklayers,” said Dr. Golembiewski. The team stresses speed as much as simplicity.
Range of motion matters, too, since legs can step over uneven ground where wheeled rigs bog down. A compact, folding frame also makes transport easier, which is essential for remote sites.
Charlotte robots can cut carbon
Buildings use a lot of energy and materials. A UN Environment Programme report notes that in 2022 the sector accounted for 37 percent of energy- and process-related carbon dioxide emissions.
Cutting the most carbon-heavy steps in early stages can have outsized effects later. That is where embodied carbon, the total emissions from making and moving materials, becomes a key metric for builders and regulators.
Charlotte’s creators claim their method avoids cement entirely while turning clean waste into durable walls. If performance and safety data hold up, that would cut both cost and emissions on the same job.
There is a workforce angle as well. Automation that handles repetitive, high-risk tasks could reduce injuries while letting smaller crews do more skilled work.
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