Rethinking Architecture with Additive Manufacturing Methods
Last summer, I was invited to speak about rapid manufacturing and related fields at Silicon Valley’s new Singularity University (singularityu.org) and to critique student projects that proposed using the technology. One student group, the Acasa Team, built upon the magic that draws us all to additive manufacturing and explored ways to amplify its world-changing potential. It was a great proposal, so here I’m summarizing this imaginative look . . .
A rural Persian craftswoman has saved enough to build a modest home for herself and her family. She logs on to the Acasa Contour-Crafting website and pinpoints her specific plot of land using a common satellite mapping tool. A generic house starter template immediately superimposes itself onto the image of the satellite view, while a perspective view opens in a separate window. The template initially depicts a single room, but as she can afford more, she drags a wall by its “handle” to create an antechamber where the family can greet guests. Doors automatically connect the two rooms, though their location is easily modified. She adds bedrooms, again by dragging the walls, windows, a kitchen including counters and a cooking island, a fireplace, and so on. Certain things automatically happen. For example, when she adds the fireplace, a chimney appears in the orthographic view. And when she drags the walls, there is a limit to how far she can move it, and there is a limited number of windows that can be installed. These are constraints built in by an invisible team of architects and civil engineers working with her behind the scenes.
The craftswoman monitors the expected construction costs depicted in a spreadsheet window that updates dynamically as the building spec changes. Next, she rotates the overall axis of the building using a rotational drag handle, and notices that the lengths of the roof overhang change. She can see that the real-time, ray-traced shadow still falls upon the base of the window sill at the simulated summer equinox—keeping the home cool in the summer—yet well above the window in the middle of winter to maximize the sun’s warmth and light. She notices an especially unusual detail not typically seen in conventional architecture: the walls have a slight sine-wave contour extruded in plan view. Satisfied, she commits to the design, clicks through to the “make it” part of Acasa’s site and rents the local gantry-based 3D “homeprinter.” Three days later, she moves into her new home.
This process builds on what rapid manufacturing does best: it creates a single, custom artifact on a per-user basis, customized with the assistance of a parametric model embedded with intelligence and expert assistance. The process begins with a web-based configurator, not dissimilar of the Kitchen Configurator offered by IKEA, which allows users to design foolproof custom kitchen layouts online. And since a Bill of Materials updates with every change, the user can easily monitor the costs of feature-creep and adjust according to her budget.
To achieve Acasa’s goals, however, myriad other systems need to be integrated into the process to ensure that the resulting structure can only be done right. Geographical Information Systems (GIS) pre-load the template with important regional considerations, including seismic information, sun direction, snow load, historic ambient temperatures, etc. Since the template is updated with the construction site’s specific requirements, it can easily marry the intent of the future homeowner with the optimization priorities of the master architects behind the programming. A wall with high sun exposure, for example, may cause the roof overhang to provide shade in the summer and increased sunlight in the winter, adjusted for ambient temperatures of the region. A room’s dimensions may be stretched to proportions preferred by the user, but only until they violate seismic considerations based on the regional codes. Similarly, snow load may determine the appropriate roof angle and span of the beams, given the known range of expected snowfall.
So although each individual homeowner makes geometry and proportion decisions within the confines of the template, they are not the exclusive “architect” on the project.
They’re always working within limits determined by optimal construction practices, and by the capabilities of the particular Contour-Crafting machine that will actualize the home.
The Acasa team’s concept has basis in reality. They met with Dr. Behrokh Khoshnevis of the University of Southern California, who has been developing the device that would be capable of turning a parameterized CAD model into a home. The device behaves much like the simple deposition modelers of today, only scaled way, way up. Think of an XY plotter attached to a cement pump with CNC trowels sculpting away at the business end. The machine is built on a gantry, comprising a wheeled motor at the base, and an armature that deposits cement like frosting on a cake.
This does not create a conventional home, which itself is a product of the processes and materials that create it. It creates something entirely new. As mentioned earlier, the walls may show a slight sine-wave in plan view. Contour can add strength, as every engineer (or egg-laying chicken) is well aware. Conventional planar walls, of course, are simply artifacts of our current construction methods, and nothing more. Domed and vaulted roof contours lend themselves well to this technology, though beams may be inserted during the fabrication to add flooring. Plumbing and wiring may live either in exposed conduits or channels ‘printed into’ the structure.
Most immediately, this process has the potential to reduce the construction costs to one-fifth of current prices. Though that does little to replace the cinderblock-and-corrugated-steel shanties that dominate the ghettos of the world, it sets the stage for improved home construction at the lower end of the economic spectrum. But the benefits go far beyond that. Homes constructed up to guidelines for thermal and seismic optimization present less of a drain on a homeowner’s budget and the world’s natural resources. Fewer forests will be deforested if a home requires less wood to maintain a comfortable temperature. And devastating earthquakes could be that much less lethal if access to seismic construction knowledge were democratized and semi-automated in this manner.
Homes built this way would be different from each other, too. Though this may sound trivial at first, imagine a town where each building is shaped by the individuality of the residents, and not from fabrication expediency. There’s something particularly dehumanizing about the bland cookie-cutter repetition seen throughout the world, where the one-size-fits-all architecture dominates the urban landscape.
Furniture, counters, stairs, benches, fire pits, cisterns, water purification,—all can be constructed directly into the structure. Prefer a gentle curve along the rear wall? A turret entryway? A circular alcove for reading? Or perhaps a concentric footprint, along the lines of the spectacular Opus One winery in Napa Valley (opusonewinery.com/architecture.html)? These may be expensive propositions using traditional means, but, using this method, a wall is a wall, whatever its shape. Costs are driven by the material and machine time. Once functional requirements are factored into the home’s design template, what qualitative improvements could follow? Perhaps the ambiance of the diffuse light in the afternoon, or the feeling of safety or security that the building offers. Maybe abstract—and often expensive—attributes resulting from cultural or religious contexts—Golden Section, Feng Shui, or other less “concrete” ideas—may be folded into the template; again, at no additional cost.
Finally, new cocktails of concrete are in development that may (currently at a premium) stand to sweeten the deal. Carbon-sequestering Calera cement (calera.com) would address that pesky CO2 problem that keeps cropping up. And translucent concrete (luccon.com) would lessen the need for indoor lighting during the daylight hours, reducing dependence on electricity.
Many of the ingredients of Acasa’s master plan are falling into place. But more development is required and, as always, form follows finance. At least one round of investment and a year of development stand between where we are now and the Age of Contour-Crafted Homes. Although this technology may first apply to terrestrial structures, as one might expect, there are plans outlining the use of this application for structures on the moon and Mars. Using local dust is certainly cheaper than hauling bags of concrete to a construction site that’s 238,000 miles away, and the less gravity, the better.
