If you, like many fans of Frank Lloyd Wright, are on the hunt for a long-lost American System-Built Home (ASBH), here is a simple tool that you can use in your field work and that may tell you if you’re warm.

One of the key features in Wright’s ASBH designs was the use of a 24 inch balloon framing scheme. Studs and joists were placed two feet apart (on center.) Every model was based on this simple but uncommon geometry, and among other benefits, it was the key to liberal window placement. It allowed Wright to hang windows in the openings between studs–often in long arrays or clustered in corners–while simplifying installation by eliminating the need for headers.

Wright’s ASBH two-foot spacing strategy had a conspicuous ripple effect throughout the portfolio. For example, nearly every design has exterior dimensions that are divisible by both 24 inches and therefore 2 feet. Homes were often 32 or 36 feet wide and 32 or 40 feet deep. And when Wright added a feature to the home, like a porch, a pier, an overhang, a chimney or a flower box, those elements would also scale in 2 foot increments.

So if you are searching for a long-lost ASBH, we suggest that you carry a simple transparent grid template with you (you can make one from a sheet of plexiglass using a T-square and a sharpie) and hold it up in front of a home you think fits the bill. If the windows, exterior walls and other elements fall neatly into the grid, you may be on to something. The grid may also help to reveal a native design beneath modifications and additions. Alternatively, take a straight-on picture and apply a grid using imaging software.

For example, here is a grid overlaying drawings of the American System-Built Models A203 and B7, designs which will both feature prominently in the upcoming book “Frank Lloyd Wright’s Forgotten House – How an Omission Transformed the Architect’s Legacy (University of Wisconsin Press), Spring 2021.

Note how each window and all wall surfaces fit within the 2X2 foot grid system (since those are the spaces without studs) and, importantly, asymmetry is suggested by shifting elements slightly within the same grid.

And a caveat: we are not experts in, nor are we suggesting, a threshold of pedigree. Just because a home fits in a grid, it is not, by default, a Wright-designed ASBH. And it is possible that a historic home has been so modified as to not pass this simple test. But that doesn’t make it any less fun to search the urban and near-suburban neighborhoods of midwestern cities and towns looking for a gem hidden in plain sight. Take your grid with you!

Images used with permission. Frank Lloyd Wright Foundation Archives: architectural drawings, ca. 1885–1959. The Frank Lloyd Wright Foundation Archives (The Museum of Modern Art | Avery Architectural & Fine Arts Library, Columbia University, New York). Frank Lloyd Wright drawings: Copyright © 2021 The Frank Lloyd Wright Foundation, Scottsdale, AZ. All rights reserved.