It wasn’t going to be easy. Renovating the midcentury modern crown jewel of SOM’s repertoire, Lever House, to include a new amenity level, boutique offices, and modern-day efficient mechanical systems—all while respecting the original design and restoring it to its original grandeur—was not for the faint of heart. 

Yet thanks to our fastidious Adaptive Reuse team, seven decades of stewardship by a single firm, and methods like petrographic testing to offer clues about sourcing the original stone, we were able to simultaneously restore deteriorating elements and modernize the iconic Lever House alongside our partners Brookfield and WatermanCLARK with, among other things, mechanical upgrades and better air quality, which will enable it to endure alongside its timeless design.

As we near the end of Preservation Month (which we honor each and every month), SOM adaptive reuse leaders Frank Mahan and Amy Garlock take us behind the scenes of a loving restoration some 20 years in the making. Here they delve into five of the original materials and our painstaking process for an authentic restoration. 

Black Limestone

Originally clad in a black limestone from Vermont, the rear wall of the plaza and lobby—the building’s backdrop—had been damaged by exposure to the elements. The black color had greyed due to oxidation, the stainless steel dividers had corroded, and in the north plaza, caulk had seeped into the stone. Some stone panels completely shifted out of alignment.

However, we were able to reset the misaligned stone panels and carefully tested through mockups the correct level of re-honing and polishing for the stone to meet the original design intent, seen through specifications and original photography. We also re-polished and sealed the stainless steel divider strips to bring back the subtle shine between panels.

White Marble

The white marble, which encloses stair towers within both the plaza and the lobby, has been reset, honed, and repaired.

The stairs and planter were originally clad in a white marble from Danby, Vermont. The SOM and Integrated Conservation Resources teams evaluated the condition of all the white marble, looking at both damage due to material loss and oxidation, as some of the veining had browned due to exposure. 

The covered exterior and interior white marble was in good condition and able to be preserved through careful repair and re-honing. Outside, exposed white marble at the planter and upper stair bulkhead were replaced with new matching material sourced from the same quarry as the original marble. 

Stainless Steel

Dented, dulled, and punctured for signs and plugs, the original stainless steel-clad columns are now restored and refinished.

We were able to remove the majority of the original stainless steel from the columns, removing dents and restoring the original stainless steel finish offsite. Where required, we matched the original stainless steel with new panels in the same finish. The stainless steel was restored primarily by hand, with skilled craftsmen reviewing the panel flatness and quality of the brushed finish.

Terrazzo

In the plaza, the pre-existing, non-original paving was in poor condition and has been fully replaced by a durable, cast-in-place concrete matching the design of Lever House’s original paving: a series of dark gray surfaces separated by a grid of light gray stripes, which follow the rhythm of the building’s stainless steel columns. The original terrazzo had deteriorated and been replaced twice already, and the existing rustic terrazzo was a poor match and in bad condition, patched due to spalling caused by New York’s freeze and thaw cycle. 

Inside, the lobby’s original terrazzo flooring has likewise been repaired and refinished. Together with the new exterior paving, this refurbishment creates a renewed sense of continuity from the outdoor space as tenants and visitors transition to the interior.

To preserve the original design intent, we worked with a concrete contractor to design two customized mixes, a light and a dark grey that matched the historic terrazzo that still existed in the lobby. We tested dozens of colors for the cement mixture and many different aggregates to find the combination that was the best match. We used petrographic testing to give us clues as to the original stone types for the aggregate makeup. 

In the lobby, the historic terrazzo was in much better condition but still had some cracks to fix and had been over-polished to a too-glossy shine. We were able to patch the cracks with careful color matching and re-hone the floor to a matte finish.

Murano Glass Mosaic Tile Wall

A glass mosaic tile wall in the elevator vestibule has been cleaned and repaired, while the luminous ceiling above features an upgraded, diffused lighting system to improve brightness and energy efficiency. 

The original murano glass tile wall at the rear of the lobby is a key piece of the overall composition. Over time, the surface had been punctured by security and fire-alarm devices, and the grout and tile had been discolored. The lighting was not original and highlighted some of the imperfections.

The team was able to reshape the hidden portions of the wall to harvest tiles that could be used to repair some of the punctures in the tile surface so that the final condition could be more seamless. We were also able to patch misaligned portions of the wall and clean and retouch all the tile and grout. 

With new lighting and refinishing, the tile wall is the beautiful focal point it was originally intended to be.

The material restoration was significant, but our work to remain good stewards of the Lever House goes beyond surface level. Read on to learn more about SOM’s original design of Lever House in 1952, our first restoration of the project in 2001, and our most recent revitalization of New York City Landmarks Preservation Commission’s first modernist landmark.