Though visible elements of green design are found throughout the residence—from the recycled-glass and concrete countertops to the energy-efficient appliances—the straw bale that’s cleverly packed to make two-foot-thick walls is perhaps Siegel’s favored sustainable solution. 

A waste product that’s typically burned in the fields after the harvest, straw both acts as an excellent insulator and reduces the amount of wood used in construction. For Siegel and Subbotin, the act of packing the straw into the walls was the perfect excuse for a party. “After the house was framed, it came time to put the straw bales between the framing,” Subbotin says. “So we invited a bunch of friends, brought food and coffee, and everyone got to work and did it.”

Over 90 percent of the baling (described by Siegel as “the modern-day experience of a barn raising”) was done in that one day. Easily inserted into the post-and-beam frame, the bales were cut to size, tied, and literally stacked within the walls of the house.  Photo 2 of 5 in Hay Is for Horses, Straw Is for Houses