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Calliope Farmhouse

Super Insulated Earth at Calliope Farm in Olympia WA

Joseph Becker, Olympia-based natural builder, utilized light straw-clay insulation, perforated plywood shear wall, and expanded cork insulation in the earthen wall system of Calliope Farm’s new residential farmhouse. Using thermal resistance R-values from existing code supplements and references from the cork manufacturer, Becker proved his innovative wall system would exceed WA Energy Code. Sufficient evidence showed that a vapor-permeable wall system adequately managed moisture, thus annulling the required vapor barrier.