Pike Loop

For the past month, a robotic arm has been building a brick wall in New York City. Call it Building-technology-as-performance-art… While the technique is admittedly pretty amazing, the technical feasibility of such a thing should not be surprising. The architects Gramazio & Kohler have gotten a lot of press for similar, albeit smaller scale, installations, and seem to have been perfecting the technology through their research at ETH Zurich for years.

One of the earliest projects to leave the workshop was this winery in Switzerland, whose undulating brick facade is constructed of panels fabricated off-site, and attached to the structural concrete frame like a standard curtain wall. Here, the technique is used to produce a pixelated 2D image of grapes (well, spheres) using bricks as the pixels…

While the photographs are compelling, it’s clear that this comes nowhere near realizing the potential of this technology. The panel size is limited, I imagine, by both the reach of the robot arm in the laboratory, and by the width of the flatbed trucks used to transport the panels. In the end, the facade remains flat.

By the time of the 2008 Venice Biennale,  The technique seemed much improved, though I imagine this piece was still constructed in sections and assembled later on site (though I may be wrong). Either way, the double curvature of the wall is impressive, especially when one considers that it was built brick-by-brick.

This is an important distinction. Throughout history, brick was a load-bearing material. Of course many buildings are still constructed in masonry, but typically concrete blocks do the heavy load-bearing, and bricks are used as a facade treatment and rainscreen.

In fact, it is very rare to find contemporary architecture that uses brick as a structural system (it may not even be allowed by code). Architects, of course, are aware of this, and while some detail their brick facades so it appears structural, others recognize the conceit, and reveal it through their details.

Frank Gehry’s Vontz Center for Molecular Studies (University of Cincinnati) is a distorted riot of deformed brick boxes. Rather than attempting to disguise the connections between the prefabricated brick panels, the architect celebrates them, using the metal surrounds to reveal the underlying structural grid, and present the brickwork as the skin treatment that it is.

While Gehry’s work seems to reveal a clear attitude towards brick, other – ‘hipper’ – firms seem unwilling to concede brick’s role as a facade treatment and facade treatment only, attempting to portray the material as the monolithic, structural mass it was in the past….

The concept renderings of SHoP‘s 290 Mulberry St show a subtle, undulating surface, but the final result is a jagged, triangulated grid of panels. The panels really could be any material, and here the use of brick is merely a shallow contextual nod to the neighborhood’s dominant materiality.

Pike Loop is so interesting as a project because it embraces the individual brick in a way that most contemporary architecture does not. Using the orthogonal module to construct complex curvilinear forms is a true step forward from the use of pixels to construct a two dimensional image (as in the earlier winery project) and the use of a mobile robot to truly automate the process is nothing short of amazing, giving architects the ability to build these undulating walls as easily as they program their CNC mills (well, maybe).

However, it’s important to note that this technology is not quite ready to replicate the work of, say, Eladio Dieste, since it still lacks one crucial component of brick construction: mortar. While the glue that binds these bricks together may be adequate for a temporary installation, and the open lattice of brickwork may produce beautiful shadows, the lack of this critical bonding agent means that the undulating screen of brick will remain a screen, and should not be mistaken for a weatherproof wall. One benefit of traditional brick construction is that the brick and mortar chemically bond to become one monolithic structure. The mortar joints serve not only to keep the bricks in place, but if properly constructed, their geometry repels water and ensures a long life for the wall. I’m curious to see if the next project from these architects begins to take these facts into consideration….

Meanwhile, I believe it will be fruitful to expand this process from brickwork to other modular construction systems. What would the Pike Loop look like if constructed from CMU blocks? Or aluminum cans? Or automobile tires?

Earthships,” championed by architect Michael Reynolds, are generally built from used tires and other garbage, and finished in concrete or plaster. This construction method has become popular in arid climates where the thermal mass of the walls aids natural ventilation. The use of recycled material appeals to environmentalists, of course, and these ebuildings have become popular in off-the-grid communities. This is certainly noble, but it lacks the academic appeal of the Pike Loop wall because it is not tied in to the computational, generative design discourse that produces such work. I believe this could change, if you simply consider the tire as the module (and maybe build a stronger robot).

Earlier this year, I did a series of studies using the Grasshopper plugin for Rhino, and attempted to design an undulating wall of tires. In a few days I was able to get a working definition, and the above image is one result. I hope to continue these studies someday, though I wonder if the large module would allow a form as evocative as that of the Swiss architects…

Anyway, it’s exciting work, and I can’t wait to see more projects like this, where the realities of construction are tied back into the design process, where algorithmic architecture is informed by real constraints, and the form and concept become stronger as a result.

For more coverage of the Pike Loop project, check these stories on Wired and BLDGBLOG, and the exhibition page at the Storefront for Art and Architecture. And finally, here’s a look at a similar process, by students at Harvard’s Graduate School of Design.


  • Thanks for the nice read. About your undulating tire wall: are the tires meant to be filled with rammed earth (like the photograph example above)? If so, how much overhang do you think will the rammed earth tire withstand without the contents spilling out the bottom? It could be a useful constraint in designing the function in Grasshopper.

    If tires are not meant to be filled with rammed earth, well forget it.

  • Thanks for the comment, Andrew. Ideally, yes, they’d be rammed earth, and you’re absolutely right… I’d have to do a series of tests to find the maximum overhang. To be honest, I doubt it could go very far, but it would be a useful constraint. I believe some of these structures are built with concrete, using the tires as a crude formwork, so it might be possibly to run rebar through the gaps… it’d be worth looking in to….

  • There was a write up in BLDGBLOG a long time ago about stacking blocks to form a canteliever counter balanced by the weight of un-fixed blocks….here it is: http://bldgblog.blogspot.com/2007/12/adventures-in-stacking.html. Obviously, not exactly the same thing, but fun at least.

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