The Milanese firm of CLS Architetti, founded in 1993 by Giovanna Cornelio, Massimiliano Locatelli, and Annamaria Scevola, has carved out a reputation for a modish modernismo style. Its portfolio includes fashion boutiques, offices, showrooms, apartments, and the Lia Rumma Contemporary Art Gallery in Milan (2009). Yet one of its most distinctive works is the office it created for itself within the confines of an ornately crepuscular 16th-century church, San Paolo Converso, not far from the Duomo. Known for its richly hued Renaissance frescos by Antonio and Vincenzo Campi, the landmarked structure was deconsecrated after World War II and recently served as the Milan outpost for Christie's.

The local church diocese knew of CLS's work and suggested to the architects that they rent the space for their studio; the only catch was that the walls could not be touched. The architects moved in at the end of 2014 after installing a four-story freestanding steel structure at the rear of the church interior in order to leave the front available for public events. The staunchly built scaffold (although it is designed to sway in an earthquake) allows 20,000 square feet of workspace to be arranged on different levels. As Locatelli describes it, architects and designers perching there have varied perspectives of the Campi brothers' frescos while catching glimpses of the outdoors through the church windows.

A major challenge was to figure out how to add illumination without fastening lamps on the walls. CLS worked with a manufacturer to create custom cold-cathode lights on dimmers mounted on the steel structure. (The firm had conducted studies to assure that the church's foundations could support the weight of the steel.) Downstairs, the crypt, with its columns and groin vaults, contains the library, model shop, and kitchen'a counterweight to the airier workspace above.