Ascent Builders

Architectural Record

By B.J. Novitski  

Bailed straw can also be used in construction without any processing at all.  One recent example is Oak Lodge, a Jesuit retreat in the Sierra Foothills, designed by Emeryville, California–based Siegel & Strain Architects and constructed by Ascent Builders of Sacramento, California. 

The designers chose straw-bale construction partly for its high insulating capacity, making evaporative cooling viable during very hot, dry summers.  Eliminating mechanical refrigeration reduces the building’s energy consumption and carbon emissions. Moreover, according to principal Henry Siegel, FAIA, the stucco on the interior and exterior provide substantial thermal mass and shear resistance to earthquakes. The bales are so tightly bound that they are effectively fire-resistant.

At Oak Lodge, the straw bale is infill in a two-story, post-and-beam structure, held in place by rebar and heavy wire mesh. The bales come directly from nearby rice fields where, until recently, they would have been burned as waste.