Few buildings are truly iconic, but one that qualifies is Frank Lloyd Wright’s Unity Temple. Completed in 1908 in the Chicago suburb of Oak Park, its place in architectural history has long been assured by its seminal synthesis of monumental massing with luminous, richly detailed interior volumes. Closed since Spring 2015 for an ambitious restoration effort led by Chicago-based preservation architect Gunny Harboe of Harboe Architects, it will be ready for reopening in time for the 150th anniversary of Wright's birth on June 8, 1867.

This early Wright masterwork was among the first nonindustrial buildings to use exposed, poured-in-place concrete—augmented by precast ornament—as its primary material. But a century of wear, exacerbated by seepage from an undersized internal drainage system—designed by Wright to avoid gutters on sixteen separate flat roofs—took its toll both inside and out. A 1973 renovation attempted to remediate the cracked and spalled exterior walls with a coating of "shotcrete" (a spray-on concrete) but problems persisted. Nine years ago, a large piece of ceiling fell down, signaling the need for a more extensive—and expensive—permanent fix.