A new kind of construction robot in Australia is raising fresh possibilities for tackling the global housing crunch. Designed to build the structural shell of a 200-square-metre home in roughly 24 hours, the system promises faster delivery, lower material use and the ability to work in places where conventional crews struggle to operate. It’s an early-stage technology, but one that hints at how innovation in robotics and materials could reshape the way homes are built.
The robot, created by Crest Robotics and Earthbuilt Technology, is named Charlotte. Unlike the tracked or wheeled construction robots seen in other projects, Charlotte moves on six legs. The spider-like stance gives it stability on loose, uneven or shifting ground—conditions where ordinary machinery tends to slip, skid or get stuck. Once the build plan is uploaded, Charlotte operates autonomously, tracing the layout of a home and stacking layer after layer of compacted earth to form thick, load-bearing walls. The process covers the wall shell and structural forms but not interior fit-outs.
The core of the system lies in Earthbuilt’s extrusion and compaction unit mounted on the robot’s chassis. Instead of cement-heavy masonry, Charlotte relies on locally available materials such as soil, sand and crushed demolition waste. These inputs are fed into tubular fabric sleeves, which are then stacked and compressed into rigid layers. The method draws from “earthbag” construction, a long-standing low-tech technique used for durable and energy-efficient structures. By refining it with robotics, the team aims to scale it faster and make it suitable for modern projects.
The advantages are clear. Using soil directly from the site reduces the need for trucking and helps keep carbon footprints low. On remote plots—particularly in rural Australia—construction timelines often slip because material supplies arrive late or require long transport routes. Charlotte’s system removes many of those dependencies. Its legged movement also allows the machine to climb over newly formed walls without damaging them, negotiate corners cleanly and maintain traction even on loose soil.
Portability is another design focus. Charlotte’s frame folds down, allowing it to be shipped compactly. The robot can be deployed with minimal ground preparation, set up quickly and adapted through modular nozzles and tamping tools. Different soil types, wall curves and layer heights can be handled by swapping components rather than redesigning the entire system. The robot can pause mid-build and resume without compromising structural continuity, which helps when weather conditions shift or when inspectors need to examine progress.
Supporters argue that this kind of rapid construction is not just a technological milestone—it responds directly to challenges the housing sector faces worldwide. Labour shortages continue to slow down projects in many markets. Weather delays, permitting lags, repeated mobilisations of materials and rising financing costs create a chain of uncertainties that ultimately push up home prices. A robot that can form the structural shell of a house in a single day compresses several of these risks into a smaller time window. Human crews are then freed to focus on plumbing, wiring, insulation and finishing—areas where craftsmanship matters most.
The sustainability angle is equally important. Earthen walls offer high thermal mass, which helps maintain indoor comfort by absorbing heat during the day and releasing it at night. They perform well in fire and resist rot when built correctly. Using recycled aggregates reduces landfill pressure from construction debris. And by limiting cement to only critical joints, the system cuts emissions significantly compared with brick or concrete construction.
There is also a more ambitious use case on the horizon: building on the Moon. Space agencies planning long-term missions need structures that shield astronauts from radiation, temperature swings and micrometeoroids. Shipping construction materials from Earth is impractical. Charlotte’s light, foldable hardware and its ability to use local materials position it as a potential candidate for lunar construction. If equipped with the right tools, the robot could theoretically gather Moon dust (regolith), compact it into dense layers and shape domes or protective berms.
Several companies are racing in this domain. ICON, under NASA’s Project Olympus, is developing systems to 3D-print lunar bases. AI SpaceFactory, winner of NASA’s 2019 habitat challenge, is working on printers and binders for regolith-based structures. Crest Robotics and Earthbuilt enter this landscape with a different approach: a legged platform that combines extrusion with compaction for stronger bonding between layers.
For all its promise, the technology still needs to prove itself to regulators. Building codes must account for the strength of compacted earth under seismic loads, its moisture performance and its fire rating. Inspectors will want reliable data, repeatability and clear testing protocols. Lenders and insurers usually follow codes, so formal recognition will be key for adoption.
Construction practices will evolve too. Routing services through thick earthen walls requires careful detailing. Roof connections and waterproofing must be adapted to the material. While robots may place the structure, human expertise remains essential to ensure long-term safety and durability.
Charlotte is not a complete solution yet, but it marks a notable step in a field trying to solve two problems at once: how to build faster on Earth, and how to build safely beyond it.
