Cantilevers—Where Architecture Meets Engineering

Frank Lloyd Wright knew how to build headline-grabbing houses. His most famous, Fallingwater, is among eight of his works recently given UNESCO World Heritage Site status. Completed in 1939, its vast concrete cantilevers—rigid structures that extend horizontally from a vertical “anchor”—project 17 feet (5 m) over and 62 feet (19 m) along a waterfall in the Pennsylvanian forest.

The cunning technique of cantilevering was ideal for Modernists—including Wright’s protégé John Lautner, designer of the 1953 Tyler House in Studio City, California—who strove to erase the sharp distinction between inside and out. Instead, they used “steel and glass to make spaces that create architectural delight in the ambiguity between indoors and out,” says architect Steve Hoedemaker of Hoedemaker Pfeiffer, one of a number of contemporary architects championing cantilevered living.

At Fallingwater, Wright’s cantilevers push domesticity into the wilderness. And with its 12-foot-long (3.6 m) cantilevered living space, Hoedemaker Pfeiffer’s Hillside Retreat, off the coast of northern Washington, follows suit.

Related: Take a Virtual Tour of a Frank Lloyd Wright Masterpiece

A good cantilever in these high-tech days involves the marrying of architecture and engineering. Previously, an engineer might just be asked for feedback on a design, but now, “the engineer is involved in the design as it moves forward,” according to Greg Faulkner of Faulkner Architects. His Creek House in Truckee, California, “is actually made up of cantilevered beams in two directions,” he explains, with the floors, walls, and roof acting as a rigid box.

Each boulder was carefully plotted in the construction documents to allow a precise interaction with the built form—Greg Faulkner

This configuration allowed the house to sit in a field of basalt, with the cantilevers hovering over one particularly large stone. “The site is strewn with large boulders that the client recognized as critical to keep intact and undisturbed,” explains Faulkner. “Each boulder was carefully plotted in the construction documents to allow a precise interaction with the built form.” To further reveal the relationship between the built form and the rocks, the house’s main access is glass and cantilevers over the boulders.

What lies beneath a cantilever has a huge impact on the design. Durbach Block Jaggers’ Holman House near Sydney, Australia, has living and dining areas that protrude over the ocean. Likewise, in Port Mouton in Nova Scotia, Canada, the sea passes beneath the 32-foot-long (10 m) cantilever of Two Hulls House by MacKay-Lyons Sweetapple Architects.

Many of the sites we work on contain slopes and require sensitivity in order to fit within the natural landscape—Greg Faulkner

Plots that would be tricky or even impossible for a conventional house are a gift for lovers of the cantilever. “Many of the sites we work on contain slopes and require sensitivity in order to fit within the natural landscape,” says Faulkner. “The cantilevered form allows the site to slip into and under the structure, forever weaving the two together.”

Related: How to Build the Perfect Forest Home

But while they may look effortless, the calculations that have brought such cantilevers into reality are often complex. Another sloped site boasting a cantilever is in the English county of Suffolk. At MVRDV’s Balancing Barn holiday home, half the length of the 98-foot-long (30 m) house hangs in mid-air over the descending slope.

Architect Gijs Rikken employed three “tricks” to stop it toppling over. “First, a concrete basement is positioned directly underneath the barn at the tipping point. This allows the volume to properly ‘lean’ on something. Second, an underground, concrete counterweight has been placed at the ‘landside’ of the barn, ensuring it doesn’t fall over the edge. Finally, the part that hovers above the slope has been constructed of light materials where possible, to reduce weight.”

Such trickery means a building can appear to defy gravity, like View Hill House in the Australian Yarra Valley. Here, architects Denton Corker Marshall rested a corten tube on the ground. A second tube of aluminum is perched on top at right angles, and juts out 20 feet (6 m) and 30 feet (9 m) front and back respectively.

As well as creating a close connection with the outside, a suspended living space gives a property more garden, so it has less impact on nature. “The absence of structure frees up the area underneath, giving unimpeded views and freedom to move,” says Neil Durbach of Durbach Block Jaggers.

Related: See the Art of Building in the Desert

This is also the case in Nuevo León, Mexico. The brief for P+0 Arquitectura’s Casa Narigua was about being sensitive to the site. “It was an unusually beautiful terrain filled with cedar trees that would thrive if touched as little as possible,” says architect David Pedroza Castañeda. At the same time, the whole house had to be located on a single floor. His solution was “to cantilever a good portion of the social area and the entirety of the master bedroom to minimize the house’s contact with the terrain.” Casa Narigua’s owner appreciates the house’s light touch: the cantilever gives “the sensation of being in contact with nature in a special way.”

Meanwhile, the steep site at Hoedemaker Pfeiffer’s Hillside Retreat made access and construction more complicated. But for Todd Beyerlein at the firm, most challenging of all was the need to preserve nearby trees, not only an integral part of the land, but providers of a knockout view. “Without the trees the room’s purpose would be defeated. With that in mind our team developed custom retaining walls capable of avoiding critical root zones, allowing trees located only a few feet from the dining room envelope to be retained.”

Related: Discover Incredible Glass Architecture

But cantilevers aren’t only a solution on generous plots. In a tight Melbourne terrace, Austin Maynard Architects decided not to extend the existing house as that would reduce the amount of natural light. Instead, they boldly put a new structure at the back of the garden—cantilevered, of course.

The absence of structure frees up the area underneath, giving unimpeded views and freedom to move—Neil Durbach

This shows a cleverly considered cantilever can fulfill a host of requirements. But Pedroza Castañeda at P+0 sounds a note of caution: “Bold structures communicate the possibilities of modern engineering, and that’s why clients want them. But we, as architects, have to be careful not to use them gratuitously.”

A non-gratuitous cantilever, on the other hand, can have aesthetic as well as practical benefits. Like Hillside Retreat: “The experience of entering the dining room is a delight,” says Hoedemaker. “There is a clear impression that you have left the stone house and entered the woods halfway up the trees.”  

On the Market

Modern Industrial in Seagrove Beach, Florida, U.S.A.

An extraordinary family beach home facing the Gulf of Mexico, this six-bedroom retreat, on the market with Go To The Beach Real Estate, sits atop a pristine sand dune. Features include a floating cantilevered wood staircase, a four-story inlaid stone wall, an infinity-edge pool, and an outdoor meditation garden set between the 6,024 sq ft (560 sq m) main home and the carriage house.

The Lakota Residence in Portland, Oregon, U.S.A.

Set on 10 sloping acres (4 ha), this home is a work of art. Designed by world-renowned architect Ned Vaivoda and on the market with Luxe Christie’s International Real Estate, the main level, where the home is entered, offers an open entertaining, dining, and living space. Meanwhile, a 983 sq ft (91 sq m) master suite juts from the top level, offering stunning views of the Cascade mountains.