The project involved a comprehensive rehabilitation of the entire building for office and gallery occupancy above the first floor and retail uses on the first floor and cellar. Subsequently, the Guggenheim Museum leased the first and second floors along with portions of the cellar, third and fourth floors for a new Soho museum, related offices and a café space.The scope of the interior renovation included a new building core including toilet rooms, new elevators and new electric and telephone rooms. All HVAC, electrical and plumbing systems throughout the building were replaced, and a new rooftop mechanical equipment room was constructed. The HVAC system was designed using state-of-the-art absorption boiler/chiller equipment, which operates on natural gas or fuel oil. This system has the advantage of generating chilled water using natural gas, freeing the building from New York's critical peak summer electrical demands.

The work began with careful documentation of the existing conditions to establish all elements of the original construction. This included detailed measurement of all storefront profiles in order to duplicate that work where it had been destroyed by subsequent renovation work. An analysis of the painting history was performed to determine the original colors. The exterior design was primarily based upon restoring all elements to their original configuration, however a unique feature of the design was the development of two new areaway stairs on the Mercer Street side of the structure to permit direct access to the cellar level which is only a half level below the sidewalk at that point. The combination of sidewalk windows and rehabilitated sidewalk vault covers bring natural light into the cellar.