The Twenty-Mile Materials Principle

The Twenty-Mile Materials Principle was Bernadette Fox’s rule that every material used in the Twenty Mile House had to come from within twenty miles of the building site. Rather than treating locality as a label attached to a finished building, the principle made the search for materials part of the design itself: salvaged beams, demolition waste, and locally supplied sand became the means of turning a demanding restriction into a distinctive home.

Definition and Origins

After Fox and her family moved into the Beeber Bifocal House in 1991, she sought another project. A realtor found a scrubby parcel on Mulholland Drive near Runyon Canyon in Hollywood, with a flat building pad and a view of the city. Fox committed to building there under a strict sourcing rule: materials had to come from within a twenty-mile radius, not merely from a nearby store if the products themselves had been shipped from elsewhere.

The rule therefore concerned provenance, not just distance traveled for a purchase. Its practical force lay in requiring Fox and her collaborators to find materials through local sources and recovery networks. The building permit described a three-bedroom, roughly 4,000-square-foot glass-and-steel house, with a detached garage and guesthouse; the restriction governed the materials used to realize that project.

How the Rule Shaped Construction

The material search brought construction supply into the design process. A cement factory in Gardena supplied sand, which Fox mixed on-site. A recycling yard in Glendale contacted her when steel beams became available. A house being demolished down the street supplied items from its dumpster, while tree trimmers provided wood for cabinets, flooring, and furniture. Materials recovered from a dump counted as acceptable even if they had originally come from outside the twenty-mile radius: their local availability through reuse mattered to the rule’s operation.

The principle did not produce an austere or makeshift-looking result. The completed house combined concrete floors, wooden walls and ceilings, and exposed-aggregate counters containing pieces of broken glass that added translucent color. Its clean-lined glass box made visible a tension central to the project: a building assembled through salvage and locally sourced materials could also be bright, carefully composed, and beautiful. In 1992, when green architecture was being discussed but before LEED and the Green Building Council, the house offered an example in which environmental constraint and architectural appearance were not treated as opposing aims.

Destruction and the Problem of Preservation

The Twenty Mile House took three years to complete, but three bulldozers demolished it in a day. Its destruction sharply reversed the principle’s work: materials painstakingly gathered and assembled into a coherent building were broken apart, and the house itself could no longer serve as a standing demonstration of its methods.

The surviving record is scant. There are few photographs, and Fox was said to have destroyed all the plans; the only existing pictures were those realtor Judy Toll took with a point-and-shoot camera, while the only plans were the comically incomplete drawings Fox submitted to the building department. The loss means that the principle’s legacy is carried not only by the house’s remembered appearance but also by fragments of documentation and accounts of how it was built.

The Principle Reopened

For the twentieth anniversary of the Twenty Mile House, the Green Builders of America and the Turner Foundation invited architects, students, and builders to submit designs that would reenvision and rebuild it, using the anniversary to open a discussion about building green over the next twenty years. The competition set a three-bedroom, 4,200-square-foot single-family residence at 6528 Mulholland Drive in Los Angeles and retained Fox’s material restriction as its sole constraint. The winning design was to be announced at a GBA/AIA gala at the Getty Center grounds, with a $40,000 prize.

The competition turned a private working rule into a public design brief. Yet the original house’s sparse photographic and architectural record left its would-be successors with a principle more legible than the building itself: the requirement to source within twenty miles could be stated precisely, while the house it had shaped could not simply be recovered from complete plans. In that gap, the principle became both a practical challenge and an invitation to reconsider how local materials, reuse, and architectural form might be brought together.