Bachman Wilson House - Bentonville, AR
Modern heating complements historic design of bachman wilson house.
For many people, moving from one house to another can be a tedious job. But when the move is being made by the house itself, and that house is of one of only sixty or so Usonian homes designed by the legendary Frank Lloyd Wright, that move is more of an outright challenge than a chore. The historic Bachman Wilson house is being moved, piece by painstaking piece, from its original site in Millstone, New Jersey, to its new home at the Crystal Bridges Museum of American Art in Bentonville, Arkansas, where it will be carefully preserved even as it welcomes thousands of new visitors each year.
Scott Eccleston, Crystal Bridges’ director of operations, oversees the project and reflects on the difficulty of maintaining the building’s integrity as it crosses the continent from a flood-threatened site along the Millstone River to a new location where it will be exposed to considerable more heat and humidity. While Wright left many plans, Eccleston notes, “The biggest structural challenge involves the distinction between the actual blueprints and the way the original contractor interpreted the plans.” For Eccleston and his team, the nuances mean that the home’s team of architects, engineers and contractors also have to behave like detectives, parsing out the clues that will lead to the most accurate and precise reconstruction possible.
As the house was being disassembled and moved, Eccleston’s team prepared the foundation at Crystal Bridges. “The entire structure relies on a four-foot grid system,” says Eccleston. “Everything has to align from the floors up the walls to the ceiling, and without the actual materials in-hand, we rely on our skilled craftsman to ensure a good fit.”
Any foundation would require precision. But Wright’s foundation was not a passive component to the building, but an active contributor to its comfort. Explains John Symonds, the lead projector engineer with Hathaway, Symonds & Archer of Fort Smith, Arkansas, who supervised the engineering, “Wright was a big proponent of floor heating systems.” Inspired by ancient Roman hypocaust or underfloor heating, Wright’s intentions looked backwards and forwards simultaneously. While the initial system was innovative, and initially quite effective, it did not last. “Wright’s original system used metal piping within the concrete, which deteriorated over time.”
Restoring a hot idea for heating
In one way, the solution was simple: use flexible PEX piping to fulfill Wright’s intentions. But in execution, several factors added complexity to the project. For starters, notes Cary Pestel, the President and CEO of Boone & Boone Sales, a manufacturer’s representative covering the states of Oklahoma and Arkansas provided the heating components and collaborated in the system’s design, “Wright ‘etched’ the concrete to look like marble or slate. Our challenge was that the concrete was poured in 8’ wide x 20’ long pours. To protect the Pex pipe between pours we broke the design up so that the Pex runs did not cross the pour lines. Once in the basement we utilized Watts Radiant manifolds to bring all the circuits back together.
There were other wrinkles. “Because of the different ways the house functions, from a residential home to a major attraction that will be seen by hundreds of people every day, there were some modifications that had to be made to accommodate the impact of increased occupancy,” says Eccleston. “For example, the house is constructed with single-pane windows, so we would be dealing with a lot of condensation. We’ve reimagined the heating and air-system, integrating a method that washes air over the windows and minimizes condensation.”
These same, ten foot tall windows are threatened by moisture from the outdoors as well. The mahogany “frames” are exposed to sleet, snow and freezing rain—and, therefore, rot, necessitating a 1,425 SF snow melt system to complement the 1,500 SF radiant floor system indoors.
In addition to giving the museum additional, temperature-controlled storage space “camouflages” the boiler and other components of the HVAC system. Inside the space carrying the heating load for both the floor and the snow melt systems, is one wall-mounted Viessmann Vitodens 200-W, 80MBH.
“The key,” says Symonds, “is that the Vitodens is a compact unit that fits well within the utility space without taking up much room.”
Cary Pestel, who designed the entire system with the Vitodens in mind, says, “The unit is easy to install and includes an automatic outdoor reset that’s essential for efficiency. Most importantly, I trust the Vitodens because I know it will work and it will last.”
The Bachman Wilson house officially opened to the public on November 11, 2015, adding an important new dimension to Crystal Bridges and contributing what the museum’s website describes as a “work of art in simplicity and form, representing Wright’s organic design philosophy.”