Where Has Construction Automation Been Successful?

Construction is famously labor intensive: direct labor makes up close to 50% of the cost of constructing a new single-family home in the US, compared to around 6 to 8% of the cost of manufacturing a car. Unsurprisingly, there’s long been interest in automating the construction process to reduce the amount of labor required, and therefore the cost of housing. The earliest attempt at automating construction I’m aware of dates to 1853, with a plastering machine invented by Isaac Hussey, and since then there have been numerous other attempts.Hussey’s plastering machine, via Scientific American, February 5, 1853.I wanted to get a better sense of what the arc of construction automation looks like over time: what things had been tried when? What worked, and what fell by the wayside? To do this, I used AI to trawl through thousands of old issues of digitized construction trade journals going back to the 19th century, looking for any example of a construction task being automated.My main takeaway is that successful construction automation basically falls into two categories. One is construction-related tasks that can be done off-site in a factory: this includes things like steel fabrication, precast concrete, window and door manufacturing, and so on. The other category is on-site tasks that are, or can be made to be, extremely factory-like: they can be done by a machine moving along a simple path, doing some repetitive motion over and over again. Historically, almost anything outside these two categories hasn’t succeeded.I started by downloading every back issue of Architectural Forum (950 issues) and House & Home (370 issues) on USModernist, and every back issue of Engineering News-Record (4,300+ issues) available on archive.org. These are trade journals that cover various aspects of the construction industry, including construction practices and methods, and cover the period from the mid-19th century up to the early 1980s. I then had Claude (Opus 5 Max) search through these issues and flag any instance of some construction task being automated. In addition to this, I also had Claude do a more general web search for examples of construction automation, which included things like looking through the archives of the International Association for Automation and Robotics in Construction (IAARC).The purpose of this wasn’t for data analysis: I wasn’t counting the number of cases by year or by category, or anything like that. This was purely an existence survey so I could see what sorts of things had been tried and were promising enough that they made it into a trade journal.As usual with a task like this, the results will be a function of what definitions you choose to operationalize the terms in your prompt. By “automation,” I mean something like “a machine does some substantial portion of a task without requiring human direction.” So this is distinct from “mechanization” or “industrialization,” where a machine is used to reduce the labor required to do some task, but that machine might still require continuous direction or direct operation from a human operator. So something like a power tool or a crane wouldn’t count as automation, because in both cases each individual movement/action of the machine is orchestrated by the human as the work is being done. A bricklaying machine that automatically placed individual bricks without a human operator directing it brick by brick, on the other hand, would count as automation.Like most definitions, this one gets fuzzy around the edges. In practice most automated systems require some degree of human oversight while they’re running, and whether that oversight counts as “directing individual movements” can be something of a judgment call. So I’d consider a road-paving machine that automatically lays down asphalt “automation,” even with a human driver monitoring the machine continuously. But something like a ride-on concrete finishing machine seems much more borderline, since that seems to require a lot more human direction on a second-by-second basis.If some construction task can be done outside an actual construction site, in a factory or factory-like environment, there’s a very good chance that, like any factory task, it can at least be partly automated.An early example of this is concrete batch plants. Through most of the 19th century, concrete was mixed manually by workers with shovels, but by the late 19th century concrete mixing started to be done by machine, and during the first half of the 20th century these became more and more automated, with things like automatic cement weighing, automatic water dispensing, and so on. On the Hoover Dam, for instance, concrete batching was “completely automated.”Steel fabrication is similar. Steel sections are, of course, a factory-produced product and always have been, and it’s not much of a leap to turn raw steel elements into building components at the factory and to partly automate those tasks. Machines to do tasks like automatically drilling holes in steel beams, automatically welding pipe seams, and automatically painting steel sections started to appear in the late 19th century and remain widely used today.More generally, essentially any building material — steel, brick, concrete block, plywood, drywall, shingles — will be produced in large volumes in a factory and thus various portions of the production process will be automated.Automatic trimming in a plywood plant in the 1950s, via YouTube.Concrete, as we’ve noted, started out as a site-produced material but eventually had its production moved off-site. We see the same trajectory with other building components. Windows and doors, for instance, used to be fabricated on-site, but those are now produced in off-site factories with many of the assembly operations automated. Floor and roof trusses were similarly originally site-produced components but are now mostly made in off-site factories with varying degrees of automation. A typical truss factory will automate the cutting of the various wood sections and the pressing of the truss plates, and some truss factories have even higher levels of automation.On-site truss fabrication in the 1950s, via House & Home.Automated roof truss manufacturing by Randek, circa 2013, via YouTube.Precast concrete is another factory-produced building component: large concrete elements like beams, walls, and columns are manufactured in an off-site plant, then trucked to the jobsite and assembled there. Precast manufacturing doesn’t necessarily have a great deal of automation, particularly in the US, but it can be highly automated.Automated precast plant in Ireland, via YouTube.This is, of course, part of the reason there’s been so much historical interest in prefabricated construction: once you move the actual construction process into a factory, you can potentially automate large fractions of it, achieving (it’s hoped) labor and cost savings. While sometimes prefabricated construction is merely conventional, labor-intensive construction done inside a warehouse, other times the process is highly automated. Levitt and Sons built a highly automated prefab plant as part of Operation Breakthrough in the 1970s, and today companies such as Autovol in the US and Gropyus in Germany run partly automated plants.Automatic cabinet door painting in a 1950s prefabrication facility, via House & Home.Automatic wall panel assembly in Autovol’s factory, circa 2021, via YouTube.The other category of successful automation is on-site tasks that can be made factory-like: a simple, repetitive motion, done over and over again as a machine moves along a simple path.A lot of the examples in this category involve concrete or asphalt. Concrete is a good candidate for this sort of automation because it’s a thick, viscous fluid; it can be squeezed into the shape of some particular container and then maintain that shape when the container is removed. So you have things like automatic concrete slipforming machines, which extrude a layer of concrete as they advance forward. Oriented horizontally, these can be used to make things like curbs, trenches, and sidewalks. Oriented vertically, these can be used to make vertical concrete structures (though I believe vertical operation is somewhat less automated).Curb-forming machine in the 1950s, via House & Home.Modern curb-forming machine, via Gomaco.Sidewalk-laying machine, via Gomaco.We also see this sort of “automatic extrusion machine” for metal. Gutter-making machines are basically portable roll-forming machines: they take in sheet metal from a coil and shape it into gutters. Similar portable machines exist for metal roof deck and metal siding.Portable gutter machine from the 1950s, via House & Home.Modern portable metal siding machine, via Stan Group.You also see this sort of automation used successfully in the construction of horizontal, continuous infrastructure. Roads, for instance, are paved with a series of specialized machines called a paving train. Working together, the machines work in sequence to rip up and roughen the existing surface of the road and then lay down a new layer of asphalt.Modern asphalt paving machine, via YouTube.Parts of railway construction can similarly be done by a series of automated machines. Maintenance tasks — things like replacing worn-out railroad ties and tamping ballast — in particular seem to be highly automated. Since the rail is already in place, this machinery can be rail-mounted, performing its various specialized tasks as it moves along the track.Rail-mounted automatic machine for removing existing railroad ties, via YouTube.Automated ballast tamping machine, via Wikipedia.Tunneling is similar. Historically tunnels were done by hand, but around the turn of the 20th century tunneling began to be done by self-propelled boring machines.Marc Brunel’s manual tunnel boring system circa 1825.From what I can tell, up through the early 2000s (and even into the 2010s), almost everything that didn’t fall