Daring Cantilevers: Architecture Takes Flight

Karen Ho Fatt says:

Thanks for explaining the ideas behind the cantilevering concepts.The pure geometric shapes certainly bring attention the the architecture. With the exception of one, they all have flat roofs. Architects still build the flat roof but more often than not, even with the engineering it seems, they still have leakage problems in our sometimes harsh, cold climate in Canada.

Rik Blanchard says:

Very interesting structures, but I'm not sure a I buy the whole "treading lightly" characterization. If the cantilevers were utilized to hover over a rock out cropping, a stream or some other natural feature, well, maybe. But these designs appear to be more about architectural gymnastics.

Becky Harris says:

Not sure if it's technically considered a cantilever (do those pixie stix actually provide any support?), but my fave is Villa Dall'ava by Rem Koolhaas. Killer ideabook by the way, I enjoyed it very much! I haven't read super-carefully yet, but is the cantilever something that came out during International Style or was it later during Brutalism?

John Hill says:

rikerb - Like the house in Portland by Skylab? There it seems obvious that the hillside requires such an approach; the weekend retreat in Oregon not so much. The house in Australia seems to follow Glenn Murcutt's lead (and vernacular buildings in the country) to raise the building above the landscape. Otherwise these examples are in suburban contexts with a desire for more open space, not necessarily a more ecological footprint.

becky - Yes, I'm a big fan of that house, too, but those legs are definitely holding up that part of the house. Have you seen the photos of the house with a giraffe in the yard? So funny yet appropriate? The OCAD building by Will Alsop in Toronto, lifted above another building on skinny diagonal stilts, is similar in vein.

I'm not sure of the earliest uses of cantilevers in architecture, but Fallingwater (1936) comes to mind at least in terms of daring. There it is used for the terraces, but I think a number of other mdoern houses also used cantilevers, like Pierre Koenig's Case Study House (below). Are there specific Brutalist examples you're thinking of? I'm sure there are many, given the use of concrete in that style.

louzucaro says:

John, thanks for this great post. Even if all of the practical reasons for cantilevers in architecture were thrown out the window, it's a visually interesting element that I always enjoy seeing.

But I do have a question: You say you practice in New York and Chicago, so I'm curious as to whether or not cantilevered structures like those are more risky in climates like ours (I live in the Chicago burbs) where our temperatures are extreme from season to season, and we have yearly freeze / thaw cycles and potentially significant frost heaves, etc.

Since I imagine there's a lot of attention paid to structural integrity when designing in a cantilevered space, for obvious reasons, do our seasons reduce or eliminate the viability of such spaces?

kdepew says:

Bad Feng Shui

John Hill says:

louzucaro - Considering that the underside of a cantilever is basically another facade or elevation, I don't see an issue with cold weather, except for the fact the underside needs to be insulated just like the more traditional side elevations. If you're referring to soil conditions, since you mention frost heave, I can guess, without having worked directly on a project with cantilevers like above, that it wouldn't be an issue. More substantial foundations may be necessary, but most likely the forces counteracting the downward forces acting upon the cantilever will be taken care above grade, with the beams, columns, bracing, etc. I recall a building (can't remember exactly which one right now) that dealt with a substantial cantilever via its deep foundation, but that is probably the exception. Again, I think the main issue is the extra expense of material, insulation, and so forth that comes from creating a cantilever's additional "facade." The insulation especially is important in cold climates more than tropical or other warm ones.

kdepew - How so? My feng shui knowledge is rudimentary, but I'd guess the oppressive volume is not desirable, but is the unimpeded flow created by lifting a good thing?

lspswr says:

kdepew -- please explain further. Very interested as we are considering a cantilevered second story house addition. Using the cantilever would give us more squarefootage than our footprint will afford. It would only extend about 5 feet over the bottom (garage) of the house, but am currently uncertain it "feels" right. Still in the early stages of designing and welcome experienced imput.

Great post, John, thanks!

iwellman1 says:

Louzucaro, check out Jack Viks home in Lake Forest, IL, a student of Mies van der Rohe. A satisfying example of a cantilevered home in the extreme conditions of Chicago.

21spring says:

I rented one and lived in it for a year froze all winter hard to heat but great views.

Debra Carrillo says:

Cantilevered designs are extreme, beautiful, dramatic and great conversation piece!!!! Love the pictures

keranbennett says:

Fantastic pictures, great architecture but would love the structural engineer to get the deserved praise that is clearly due!