Here’s why the future of bricklaying might just be robots

In our latest episode of Lexicon, Monumental founder and CEO Salar al Khafaji joined us to discuss why construction may be one of technology’s most overlooked industries. From the challenge of deploying autonomous robots on unpredictable building sites to the possibility of using fleets of specialised machines to tackle rising construction costs and housing shortages, the conversation explores what it takes to move robotics out of the laboratory and into the real world. Also, subscribe to IE+ for premium insights and exclusive content! Bringing robotics into construction In al Khafaji’s view, construction has received less attention from technology companies than its economic and social importance warranted. Before founding the company, al Khafaji had created data visualisation firm Silk, later acquired by Palantir. His next venture, he said, needed to have a more tangible impact. “I very quickly realised that meaningful to me meant it had to be physical,” he said. “How much can I achieve by basically building dashboards on computer screens?” he added. Construction stood out because of its scale, limited productivity growth and effect on housing costs. “Construction is really, really big,” he said. “Technology people and technology founders deeply underrate it,” he added. To this end, Monumental has developed autonomous robots that transport materials and build brick walls on commercial sites. But al Khafaji said operating outside controlled environments introduced a very different set of challenges. “Everything changes,” he said. “Ground truth is the only thing that matters to us, and ground truth is physically being there.” Changing light, weather, surfaces, and materials could all affect sensors and computer vision systems, making real-world deployment essential to improving the technology. “You can’t sit down, even as a very talented engineer, and write down all the things you’re going to encounter and engineer ahead of them,” he said. “You have to experience them.” The company collected data from every brick its robots placed, building what al Khafaji jokingly called “the biggest dataset on bricks in the world.” And even before laying a brick, the robots had to understand their precise position, interpret building plans and determine where each wall and opening belonged. “You need to understand the site, localise in a precise way, and then understand the intent of what needs to be built,” he said. “Only then does the robotics part actually start.” Teaching robots to build Physical materials, al Khafaji explained, add another layer of difficulty. Mortar is a non-Newtonian fluid, meaning its behaviour changes under different conditions and forces. Monumental uses load sensors to monitor pressure while placing bricks and adjusts its operations according to the mortar’s viscosity, humidity, and other variables. Individual bricks are not uniform either, as they can vary in size and shape or arrive with chipped and curved edges. “We photograph every brick as we’re picking it up and as we’re laying it with a 3D camera,” al Khafaji said. “Every brick is different.” Some misshapen units are known within the company as “banana bricks.” Its software can detect those variations and adjust each brick’s position accordingly. The system also incorporates knowledge learned from experienced masons. A human bricklayer might rotate a chipped brick to keep the visible face of the wall level and attractive. Monumental attempted to encode comparable decisions into its technology. “All the things that make masonry beautiful are encoded in that knowledge and in dealing with that variety,” he said. A single Monumental robot, he explained, can lay approximately as many bricks during a shift as one human mason. However, he noted that speed per robot was not the company’s most important measure. “Are we going to get fully autonomous bricklayers and then have humans with a wheelbarrow bringing them bricks every 15 minutes?” he asked. “That doesn’t make sense. That makes humans do the dumb part, and robots do the hard part.” “Instead of going from 100 to zero throughput, you went down by 12%,” he said. Selling walls rather than robots Monumental presents itself as a construction company rather than a robotics one. Al Khafaji explained that this model reflects the way contractors already operate. Customers, he told us, want a wall delivered to an agreed specification, schedule and price, however it is delivered. “We almost ignore the robotics part and almost ignore all the autonomy,” he said. “We’re just telling you: ‘I’m going to deliver.’” During Monumental’s early projects, the company promised to hire human masons at its own expense if its technology failed. “It’s my problem. It’s my risk,” he said. “It’s my job to make the technology work.” Al Khafaji explained that the long-term objective was to make construction more affordable, although he acknowledged that the company had not yet achieved that at scale. The use of robotics also creates a detailed digital record of the building process. Monumental can, therefore, simulate a project before beginning work, calculate the required number of robots and estimate when materials would be needed. Once on site, the company generates a three-dimensional model and compares it with the architectural plans. If a doorway intended to measure 1,200 millimetres was several millimetres out, the system could adjust joint sizes, select different bricks or cut materials. “When we deliver a building, we can actually give you a report of every individual brick that we laid,” al Khafaji said. He added that the robots are the visible part of a wider change to construction planning, monitoring and quality control. “The robots are the cool part that everyone sees, but it fundamentally changes the whole industry,” he said. Addressing the construction labour shortage Al Khafaji rejected the suggestion that Monumental’s robots will likely cause widespread unemployment among bricklayers. Construction companies already struggle to recruit sufficient skilled workers, while many existing workers were approaching retirement. “We will need to deploy thousands and thousands of robots before we can even plug the gaps in this industry in one trade,” he said. The physical demands of construction also cause people to retire earlier than workers in many other industries. Monumental wants its machines to perform the most repetitive and dangerous tasks, including work on scaffolding. Its robot operators, on the other hand, can remain involved in physical construction without spending their days carrying materials or working on their knees. “They get real meaning out of being able to say, ‘I built a house this week,’” he said. “But we’re taking away the hard physical labour, and they’re not doing the dangerous part of the job.” Al Khafaji said this could create new technical roles and help construction appeal to younger workers. “You’re actually changing the nature of the job in a very exciting way,” he added. “Hopefully, we’re making the industry sexy again.” Building faster without sacrificing design Monumental intends to expand beyond bricklaying into other parts of constructing a building’s shell. Its next steps included different types of blockwork, insulation panels and other dimensional building components. Al Khafaji estimated that its underlying technology could eventually automate between 50% and 60% of this phase, although considerable engineering work remained. With enough coordinated machines completing different trades, construction could also become substantially faster. “You could say, ‘I can build a house in a day,’” he said. “It is sort of science fiction, but fundamentally, ignoring a few exceptions, it’s actually true.” Al Khafaji argues that automation did not have to produce rows of identical prefabricated buildings. Flexible robots could instead help the industry construct distinctive buildings more efficiently. “It would be a shame if we ended up with thousands of identical cheap homes because we had no alternatives,” he said. “You can actually build beautiful things this way.” For al Khafaji, better construction was not simply about completing more buildings. It was also about recovering quality and ambition that had been lost. “We’re so much richer, and we’re building worse than a century ago, almost everywhere in the world,” he said. “It is a very sad feature that I’m very excited to solve.”