Farnsworth House: Mies van der Rohe's Steel and Glass

On a wooded floodplain beside the Fox River near Plano, Illinois, Ludwig Mies van der Rohe built a single glass room raised above the ground on white steel columns. Designed for the Chicago physician Edith Farnsworth and completed in 1951, the farnsworth house is one of the purest expressions of the steel-and-glass modernism that Mies had been developing since the Barcelona Pavilion two decades earlier. It is also a building whose site has repeatedly tested its design.

This article looks at the house as both architecture and structure: how the frame is arranged, why the floor is lifted, how the glass enclosure performs and what the history of flooding reveals about designing in a floodplain.

A weekend retreat on the Fox River

Edith Farnsworth commissioned the house as a country retreat in the late 1940s. Work began in 1949 and the house was completed in 1951. The site is low-lying meadow and woodland along the river, a setting of great beauty that floods periodically. Mies chose to place the house close to the water rather than on higher ground, accepting the flood risk in exchange for the relationship with the river and the trees.

The relationship between client and architect broke down over the cost of the project, and the dispute ended in litigation. The episode is often retold as a cautionary tale about budgets and expectations on architect-led houses. For the purposes of this article it is enough to note that the building that resulted is one of the most influential houses of the century.

The structure: eight columns and two slabs

The farnsworth house is structurally simple to describe. Two horizontal planes, a floor slab and a roof slab, are carried by eight steel columns arranged in two rows of four. The columns stand outside the line of the glass, and the slabs are attached to their inner faces, so the planes appear to hang between the columns rather than sit on top of them. A separate, lower terrace slab steps down towards the ground on the approach side, reached by broad travertine steps.

The steel is painted white, and the connections were welded and finished so that fixings are not visible, reinforcing the impression of a few clean lines in space. That level of finish is costly. Steelwork that is normally hidden behind cladding becomes the architecture, and every weld, edge and junction must be executed to a standard that conventional buildings never require. Our guide to steel versus concrete structures explains why steel suits this kind of slender, exposed frame.

Why the columns sit outside

Placing the columns outside the glass has several consequences. The interior is entirely free of structure, a single room divided only by a central service core containing bathrooms, kitchen fittings and a fireplace. The glass walls run uninterrupted between floor and roof. And the frame becomes a visible order on the exterior, with the slabs projecting slightly beyond the end columns as short cantilevers that make the planes seem to float.

Lifting the floor above the floodplain

The main floor is raised well above the ground, by a little over five feet according to the house’s National Register documentation. The decision serves both an image and a practical purpose. Architecturally it detaches the house from the ground and lets the meadow run beneath it. Practically, it was meant to keep the living floor above ordinary flood levels, with water free to flow under the slab rather than being blocked by a solid base.

That reasoning is sound in principle, and it is the same logic behind raised houses in many flood-prone and tropical regions. The difficulty is that the height was set against the floods Mies anticipated, not against the most severe events the river has since produced. Upstream development has changed how the Fox River behaves, and major floods have overtopped the floor more than once, most seriously in 1996, when water rose well into the house and damaged its finishes and furniture. Further flooding occurred in 2008.

After such events the house has been restored and its custodians have studied options for flood protection, including ways of lifting the house temporarily during a flood. For engineers, the case is a clear example of why flood levels must be set against credible future conditions, not just past records, and why a building’s resilience depends on its catchment as much as on its own design.

The glass enclosure and its performance

The walls are large sheets of single glazing set in steel frames between the slabs. In the 1950s, this offered transparency at the cost of thermal performance. The house was heated by a system embedded in the travertine floor, but in a climate with hot, humid summers and cold winters a single-glazed box with limited ventilation was hard to keep comfortable. Condensation, overheating in summer and insects in the riverside setting were recurring complaints in accounts of the house’s early life.

These issues are not unique to the farnsworth house; they are inherent in the fully glazed pavilion as a type. Modern glazing, with laminated and coated units, solar control and properly designed natural ventilation, can mitigate them, but the trade-off between transparency and comfort never disappears. Our guide to structural glass covers how contemporary glass assemblies are engineered for both strength and performance.

Ownership, preservation and legacy

Edith Farnsworth sold the house in 1972 to the British developer Peter Palumbo, who restored it and kept it as a private residence and collection. In 2003 it was sold at auction and acquired by the National Trust for Historic Preservation, and it is now operated as a house museum. It has been listed as a National Historic Landmark.

Its influence on later architecture is hard to overstate. The idea of a single, column-free glass room, with services gathered in a core and structure expressed outside the envelope, shaped houses, pavilions and office buildings for decades. Philip Johnson’s own Glass House in Connecticut, completed in 1949, was developed with knowledge of Mies’s design for Farnsworth. Both are now set pieces in any survey of famous buildings.

What engineers take from the Farnsworth House

The house rewards close study for three reasons. First, it shows how a minimal frame of a few columns and two slabs can define an entire building when connections and finishes are handled with discipline. Second, it shows the real cost of exposed structure: everything must be designed, fabricated and maintained to a visible standard. Third, its flooding history is a practical lesson in risk. Designing for a site means understanding how that site may change over the life of the building.

In our consulting work, the same questions arise on raised houses, glass pavilions and riverside sites everywhere: what level the floor should sit at, how the structure will handle water, how the glazing will perform in the local climate, and how the exposed steel will be protected from corrosion over decades.

Frequently asked questions

Who designed the Farnsworth House?

The house was designed by Ludwig Mies van der Rohe for Dr Edith Farnsworth and was completed in 1951 on a site beside the Fox River near Plano, Illinois.

Why is the Farnsworth House raised off the ground?

The floor was lifted a little over five feet above the floodplain so that the meadow could run beneath it and ordinary floods could pass under the slab, although several major floods have since risen above the floor.

How is the Farnsworth House structured?

A floor slab and a roof slab are attached to eight white-painted steel columns arranged in two rows of four, with the columns standing outside the glass so that the interior is a single structure-free room around a central service core.

Has the Farnsworth House flooded?

Yes, the Fox River has flooded the house several times, most seriously in 1996 and again in 2008, and each event has required restoration of finishes and furnishings.

Who owns the Farnsworth House now?

The National Trust for Historic Preservation acquired the house at auction in 2003 after three decades of ownership by Peter Palumbo, and it now operates as a house museum.

Building near water or designing a raised steel frame with large areas of glass? Talk to our consultancy or get in touch.