John Milner Architects was responsible for the interior restoration and conservation of the Sanctuary structure, which also included the integration of new and restored lighting, organ improvements and acoustical treatments. The interior of the Gothic-Revival building incorporates finely carved limestone, poly-chromed plaster and wood ceilings, leaded-glass windows and intricately carved woodwork. The sanctuary of The Fourth Presbyterian Church of Chicago, a Michigan Avenue landmark, was designed in 1912 by Ralph Adams Cram.