Remodeling the Construction Industry
As the construction industry continues to modernize, 3D printing could play a key role in project delivery. The technology offers many advantages: great freedom of design, accelerated delivery, reduced labor needs, and a lower environmental impact. Several large building contractors and suppliers have made serious investments and strategic moves in this area. And startups with demonstration projects are proliferating.
From a Niche market to a larger more Mainstream Market
It will be some time before 3D printing can fully compete with conventional more traditional ways of construction. Various obstacles must be overcome, relating to equipment costs, technical limitations, special skills, regulation, and client skepticism. Our analysis, however, suggests a viable business case within a few years for selected applications and a steady rise in uptake. It also suggests a transformation of the value chain—an interim emphasis on 3D-printed turnkey projects giving way to a more specialist model in the long term, with contractors buying or leasing printed structures or printing equipment.
Implications for Stakeholders
Contractors and suppliers can take various steps to exploit the 3D-printing revolution since it is highly unlikely it will go away because it is the future. And governments can foster it by shaping the regulatory environment since it will take over the market of conventional methods of buildings since it has so many advantages.
The construction industry has traditionally been very conservative and slow to innovate and unsuccessful at boosting productivity. Many companies, however, have recently embarked on a makeover, specifically by exploiting digital technologies. Until the stumbled upon 3D printing and that’s when it got interesting.
The term 3D printing refers to the production of physical objects layer-by-layer by an automated and usually computer-controlled machine. The machine, most often guided by digital 3D models, either melts metal or powdered solids or ejects liquid or semi liquid materials. Such versatility is due to three main factors: the variety of suitable materials (notably, polymers, metals, ceramics, and mortar or concrete); the almost limitless freedom of design; and the ability to fabricate complex shapes onsite or offsite, flexibly and inexpensively. Add to those characteristics the power of automated and autonomous production, and you have a near-perfect match for the construction industry.
3D printing will become a common or even standard feature in the fabrication process. The timeline and details remain uncertain. For almost a decade now, researchers have been investigating and refining techniques for 3D printing, or additive manufacturing, in construction. Several specialist companies have emerged, and several large established companies—not just construction firms but also manufacturers of building materials—has started investing in earnest. There is a strong sense of anticipation. But several issues first need to be resolved: how ready the market really is; how ready the industry is to embrace rather than resist the creative-disruptive force that 3D printing represents; how ready the technology itself is; and how companies should best leverage the technology and adapt to it.
A Natural Fit for Construction
The adoption of 3D printing by the construction industry has, sure enough, been accelerating. The reasons for this upswing can be summarized as follows:
- Technological Advances. The equipment and materials for 3D printing in construction are improving constantly, and their costs are falling. “Movie and Novel types” of printers are becoming available—those that exploit robotics more ingeniously, for instance, or are better adapted to compound materials—and are enabling new applications. Hardly a month goes by without the demonstration of some new device or technique by a go-getting startup or a major research institution such as MIT, ETH Zurich, TU Delft, or Loughborough University.
- Strategic Moves by Established Construction Companies. The big-name construction companies will have to adapt to the new reality, whether they like it or not, and several have made the strategic decision to be early adopters of the new technology. In February 2017, France’s leading construction firm, Vinci, bought a stake in the French startup XtreeE, which specializes in printing concrete structural elements. Bouygues, another French construction giant, is partnering with the University of Nantes team that helped develop the Batiprint3D process, and is starting to print social housing in Nantes. The multinational contractor AECOM has signed a three-year agreement with Winsun to jointly enhance their client work in 3D-printing in construction.
- New Entrants. The number of companies active in 3D printing in construction has soared recently. At the start of 2013, there were barely 20 startups in the field; today, there are about 65 offering services such as prototyping solutions for architects and engineers, software and design tools, and large structural components or even entire buildings.
- Political Push. Regulation, subsidies, and other public policy measures are encouraging the adoption of 3D printing in construction in many parts of the world. In the Middle East, the UAE is aiming for 25% of new buildings to be printed by 2030; and Saudi Arabia seems intent on using 3D printing to reduce its housing deficit. Elsewhere, the United Kingdom has developed a National Strategy for Additive Manufacturing, which estimates that in construction alone the technology could contribute more than $1 billion to annual GDP and create 15,000 jobs by 2025. In the United States, the Department of Defense is studying the idea of printing military barracks, using local materials, for its personnel worldwide.
Stimulated by these four factors, 3D printing in construction will continue increasing its participation in the sector. The various forms and applications of the technology are already well defined and classified.
types of 3D-printing technology
Three types of 3D-printing technology are used in the construction industry, each with distinctive applications and features.
Material Extrusion Also known as deposition modeling, concrete printing, or contour crafting, this technique involves extruding material through one or more nozzles mounted on a robot arm, gantry, or crane. The process differs from the long-established sprayed-concrete method, in that it applies the material precisely and takes a layer-by-layer approach. It was developed for construction by such pioneers as Behrokh Khoshnevis, the founder of Contour Crafting, and is valued by many companies for its versatility in materials (concrete or mortar, gypsum, ceramics, polymers) and applications.
Powder Bonding Also known as selective state change or binder jetting, this technique involves applying a laser or a liquid (adhesive or solvent) to a bed of sand mix, powdered metal, or other granulate feedstock, thereby fusing the material and creating a firm solid such as sandstone or steel. During the chemical or heat reaction, each new layer of material hardens on top of the previous layer. In the construction industry, the process was developed by Enrico Dini and his company D-Shape with the aim of producing overhangs and geometrically complex objects that are not possible with conventional building methods.
Wire Arc Additive Manufacturing (WAAM) This method involves the use of an electric arc to melt wire and a robotic welder or drip feeder to construct a metal object drop by drop. The process has gained wide publicity through MX3D’s bridge project in Amsterdam. At MIT, the Mediated Matter Group, in developing its digital construction platform system, has been experimenting with a related technique—robotic chain welding—to create rigid reinforcement structures.
The construction industry has, to date, adopted six main applications of 3D printing. They vary not just in character but also in their maturity. They are Buildings, Bridges, Printed Molds, Building Components, Architectural Models and Interior Design.
3D printing have identified a number of ways the technology is benefiting, or could be benefiting, the construction sector.
- Freedom of Design By reducing the costs associated with nonstandard shapes, 3D printing gives free rein to architects and designers. The technology can turn complex designs into real structures that are beyond the capabilities of traditional builders.
- Autonomous Construction. The skills shortage affecting the construction industry in many high-income countries could soon become less relevant—autonomous or semiautonomous 3D printers require minimal human surveillance, their effect will be to reduce overall equipment costs, which typically account for 20% to 25% of the cost of a traditional construction project.
- Predictability and Speed of Delivery By operating 24/7 and by reducing onsite glitches and hence delays, 3D printers can cut construction times dramatically. Deliveries of building materials, for instance, will dwindle, as will the complex interactions between various trades.
- Sustainability 3D printing will reduce the construction sector’s harmful impact on the environment. For a start, a large proportion of the feedstock—as much as 50%, according to some experts—could be recycled material. Furthermore, 3D printing allows contractors to use less material in the first place: by creating complex shapes, such as overhangs and folds, for functions such as insulation and shading, it dispenses with the need for additional material or separate structural units. In many cases, the form enables the function.
- Special Properties Thanks to its mastery of “topology optimization”—through the use of conical, hollow, or honeycomb structures, for example—3D printing can endow its products with special properties, such as increased tensile strength or enhanced thermal insulation, without adding to their weight. Once again, form enables function.
The full benefits will materialize only when 3D printing is applied at scale. That time lies in the future—exactly how far depends on the rate at which the various obstacles are overcome.
One day in the near future perhaps, large buildings will be printed in their entirety by a single printer, with no onsite human input apart from the pressing of a switch and the topping up of feedstock. That is a very distant prospect. A more modest and realistic vision involves retaining several separate procedures and autonomous or semi-autonomous systems—including reinforcement, concrete extrusion, surface milling, and insulation—but integrating them closely with one another and with human workers. In the more immediate future, 3D printing in construction will extend its role further by popularizing and refining its special applications, such as printed molds or complex components, and keeping pace with ever more complex and ambitious designs. The momentum should continue, provided that the investment continues flowing as well.
Romain de Laubier is a partner and managing director in the Paris office of The Boston Consulting Group and the leader of the firm’s building materials topic worldwide. He specializes in the construction industry, building materials, and infrastructure, with an emphasis on digital strategy. You may contact him by email at email@example.com.
Marius Wunder is a knowledge expert and team manager in BCG’s Munich office, where he focuses on construction and building materials. You may contact him by email at wunder.marius@ bcg.com.
Sven Witthöft is a consultant in the firm’s Cologne office. He specializes in digital technologies and new business models in construction and building materials. You may contact him by email at firstname.lastname@example.org.
Christoph Rothballer is a principal in BCG’s Munich office and an expert on infrastructure. You may contact him by email at email@example.com.