With the recent move of 3D construction printing out of the research labs and onto construction jobsites, there is a disconnect between the available technology and construction law. Bryan Kroes discusses the future of 3D printing and construction law.
Bryan T. Kroes, Hurtado Zimmerman SC – Wauwatosa, Wisconsin
3D printing is sometimes referred to as additive manufacturing, because of the ability to create three-dimensional solid objects by layering materials on top of one another.
While 3D printing was once futuristic technology, it is now commonplace throughout a variety of industries. Because 3D printers can print any shape that can be imagined, the applications are almost limitless.
Many toys, models, and knick-knacks can be simply designed and quickly mass produced.1 The automotive industry has started using 3D printing for certain vehicle parts and even entire cars, starting with “Strati,” the first 3D printed electric car printed in 2014. The health care industry has been using 3D printed medical devices and implants that can be custom-made for a patient’s specific physiology.2 In fashion, Adidas is currently marketing a shoe with a 3D printed sole and Nike markets a shoe with a 3D printed textile upper. Average consumers can even purchase a simple desktop 3D printer for personal use starting as low as $250.
The construction industry is no exception, and one where 3D printing innovations are advancing at a rapid rate. A number of companies around the globe have been experimenting with 3D printed building components such as bricks, structural components, and even full structures.
Even NASA has experimented with building 3D printed habitats on Mars.
In 2018, two companies named ICON and New Story joined forces to claim the title of the first companies in America to secure a building permit and build a 3D printed home. Located in Austin, Texas, the 350 square foot home was printed using a single Vulcan I 3D printer, in approximately 48 hours at a cost of $10,000.
The structure was printed using a proprietary concrete-like material, however, the roof, windows, doors, electrical wiring, and plumbing were not. After the success of the first home, ICON released its Vulcan II printer, which it says can produce homes measuring up to 2,000 square feet in size, or multiple homes in the same time it took the Vulcan I printer. The companies have reportedly started to print a community of homes to an underserved population, with each home running from 600 to 800 square feet with a targeted cost of approximately $4,000 per home.
In early 2019, Sunconomy LLC of Austin, Texas, announced WePrintHouses, an all-in-one 3D printed home technology system that will be licensed by select builders across the U.S. The company boasts that it is the first 3D home printing system that is able to readily obtain permits and meet U.S. building codes.
WePrintHouses’ printing system is comprised of a movable platform containing a proprietary printer head that prints entire houses with a “hydrophobic, self-binding, geopolymer cement,” which tends to operate more like an inkjet printer. The geopolymer cement is claimed to be sturdier and less environmentally harmful than concrete made with Portland cement. This allows for reinforcing bars to be designed into the floors, walls and roof systems to meet building codes. The company says that its system eliminates the need for masons, drywall installers, roofers, carpenters, and other trades, which results in not only quicker overall build time, but also elimination of labor shortages and materials waste. According to the company, the walls are designed and tested to withstand “fire, hurricane and tornadic force winds, 8.0+ earthquakes, hail and flooding.”3
In October 2019, Apis Cor announced that it completed the largest 3D-printed building in the world in Dubai. The two-story administrative office building stands 31 feet tall, has an area of 6,889 square feet, and had its walls printed using only one printer in 21 days. The insulation, roof, foundation and windows were installed using traditional construction methods. This build comes on the heels of the “Dubai 3D Printing Strategy” mandate that by 2025, every new building will be 25% 3D printed.
Arizona-based Armatron Systems in December 2019 announced that it secured a patent for an on-site 3D printer that reportedly can create a concrete slab as long as 60 feet in less than one minute. Concrete slabs can range in thickness from a quarter inch to 30 inches. The company reports that its printer uses a “slip-form mold extrusion system” that limits bubbles and air in the concrete that shortens the curing process, allowing the concrete to be ready to support weigh moments after being laid.
Armatron further boasts that the printer system is lightweight, with no piece weighing more than 70 pounds, and can be set up and ready to cast concrete in 35 to 45 minutes. An added benefit is that any concrete can be used. While the system can create a concrete slab as long as 60 feet in less than one minute, the company says the average operating pace is about 20 feet per minute. As such, the company estimates that the printer can build a 1,500 square foot space in two days, from foundation to roof.
New York-based SQ4D, an offshoot of S-Squared 3D Printers, completed in January construction of a new building, in what it claims is the “largest permitted 3D printed home in the world.” The structure is 1,900 square feet, and was built over an eight-day period with a reported 48 hours of print time. The home was reported to be entirely printed and built on-site using less than $6,000 in materials.
The challenge, as often happens with new technology, is that the law sometimes cannot catch up with innovation fast enough.
With the advent of 3D printing in construction moving out of the research labs and onto construction jobsites in the last few years, there is a disconnect between the available technology on one hand, and building code, permitting, inspection authorities, and contract provisions on the other hand.
All of this technology is moving at a lightning-quick speed. However, as of this writing, most municipalities do not have any codes relating to 3D printing or additive technology.
Additionally, while suites of construction contracts from ConsensusDocs and AIA have recently-adopted Building Information Modeling addenda, they do not anticipate actual construction to be completed by 3D printing techniques. If someone wants to build a 3D printed building, they have to work by analogy. Similarly, case law has not yet been documented addressing issues that may come up with 3D printed structures. Building inspectors will encounter similar hurdles.
In one major step forward, in April 2019, the International Code Council introduced the 3D Printed Building Construction Appendix 4 to modify the 2018 International Residential Code (IRC). The 2019 Public Comment Hearings were held in October 2019, and the Online Governmental Consensus Vote on the Public Comment Hearings was closed in December 2019. Both vote tallies showed that the 3D Printed Building Construction Appendix was approved as modified by public comment. The ultimate results are not final, however according the preliminary results, it appears that the Appendix may ultimately be incorporated into the IRC.
If the 3D Printed Building Appendix is adopted, buildings and structures fabricated in whole or in part using 3D printed construction techniques will finally have one benchmark for design, construction, and inspection.
Most of the proposed IRC Appendix incorporates by reference the Underwriters Laboratories’ UL 3401, Outline of Investigation for 3D Printed Building Construction. The first edition of UL 3401 was published Oct. 25, 2019, and can be purchased through the UL Standards Sales Site.
According to an April 2019 news story, “UL 3401 covers the evaluation of building structures and building assemblies such as panels, walls, partitions, floors, ceilings, roofs, columns, and beams fabricated using an additive manufacturing process.”5 It includes requirements to monitor, display, and provide reports on key production parameters that are critical to ensure that building assemblies are consistently produced within certain design specifications and tolerances. It also requires documentation to be available to confirm the production parameters used during the build.6
In addition, the UL 3401 evaluation examines the fabrication process, and establishes production controls to determine that 3D printed structures consistently meet certain criteria for mechanical strength, fire performance, air and water barrier, thermal insulation, indoor air quality, and durability.7
While the proposed IRC Appendix shows one small step toward the law catching up with innovation, there are still multiple hurdles to overcome at every step. Local building codes will have to be tailored to accommodate 3D printing, with permitting and building inspectors being educated in the mechanics of 3D printed structures.
Architects will have to quickly become familiar with possibilities and limitations of 3D printed components and the interface with traditional construction techniques. Insurance coverage may have to be tailored accordingly. The major suites of construction contracts may also want to consider developing an addendum related to 3D printed structures.
Construction attorneys will further have to be careful to think through the additive manufacturing process, taking into account exact method of 3D printing, manufacture and design when writing contracts.
Despite the innovation, a potential countervailing view is that the legal issues may stay very much the same, such that construction contracts may not have to be modified much at all. Disputes will still likely be over the same general categories of cost, schedule, and defects. If a 3D printed building comes in over budget and behind schedule, with a roof leak added in for good measure, the owner will still be looking at the general contractor for correction and contribution.
As 3D printed structures become increasingly a part of the construction industry, these issues will undoubtedly be tested. While the innovation is still ramping up, construction attorneys should become familiar with the various 3D printing techniques in use, so that if a client comes in the door with an idea to construct a 3D printed building, potential liabilities can be evaluated and a proper measures put in place to ensure a successful project.
This article was originally published on the State Bar of Wisconsin’s Construction and Public Contract Law Section Blog. Visit the State Bar sections or the Construction and Public Contract Law Section web pages to learn more about the benefits of section membership.
 See, e.g.,Top 10 toys to make for your 3D printed Christmas, 3Dnatives.com; 19 3D Printed Toys You Can Print for Your Kids Today, tutorial45.com.
 See, e.g., 3D Printing of Medical Devices, FDA.gov.