Exterior, Wood, Metal, Gable, House, Farmhouse, Green, and Shed “Often when we talk about sustainability we focus on the gadgetry, what makes things feasible off grid,” Moffitt says. “But to me there are more interesting things in passive design that rely on the available sun and wind.” An eight-panel solar array does chip in significantly, generating all the electricity the house needs.  Best Exterior Farmhouse Metal Shed Photos from A Sustainably Built Home in Rural Ontario