Bronze Age: Modern Glass Performance Is Integrated with Art Deco Design via Original Ornate Bronze Window Frames in Detroit’s Albert Kahn Building

historic windows, Albert Kahn Building, NSG Pilkington, Spacia

Situated about 3 miles north of downtown Detroit, the New Center Area Historic District is indeed steeped in civic and architectural history. It ascended during the business boom of the 1920s when Detroit became the epicenter for America’s burgeoning love affair with automobiles. The heart of the district is defined by three major buildings that rose as landmarks during the period: the Neo-Classical General Motors Building in 1923; the Art Deco Fisher Building (considered by many as Detroit’s largest art object) in 1928; and Fisher’s similarly Deco neighbor, the New Center Building, in 1931.

The New Center Building once housed the offices of Albert Kahn, one of Detroit’s most well-known and prolific architects. Kahn’s design impact can be felt throughout Michigan, and he made a significant contribution to the architectural fabric of the city of Detroit.

“The New Center Building, renamed the Albert Kahn Building in 1988, was constructed as a limestone, Art Deco reflection of the Fisher Building,” explains Jennifer Elmore, AIA, NCARB, associate director of Architecture with Kraemer Design Group. “The building has a first-level mezzanine and had been home to hundreds of retail establishments and offices over the past 90 years. It was listed on the National Register of Historic Places in 1980.”

Original bronze window frames were in beautiful condition, so the design team sought a glass solution that would increase the thermal performance without replacing the frames.

Preserving Kahn’s work around the metro area is important to those who respect the city’s rich history. Sometimes that can mean upgrading and finding new uses for classic structures and finding ways to bring their performance into the future while honoring the past. Such was the case with the Albert Kahn Building, particularly its original and beautiful bronze window frames.

Residential Conversion

A joint venture was comprised of Northern Equities Group and Lutz Real Estate Investments as they sought to revitalize the building and transform the property into retail spaces and 206 apartment units. They turned to Kraemer Design Group to serve as architect, interior designer and historic consultant while Cunningham-Limp came on board as construction manager.

As with most historic restorations and renovations, there was a lot to balance. The project team was faced not only with changing the utility of the building and upgrading its performance to present-day standards but doing all this while being respectful to the beautiful aesthetic of the original design.

“The goal and challenge came in when asking ourselves how to transition this type of office space into residential apartments and spaces that relate to the grand historic lobby on the first floor,” Elmore recalls. “How could we translate those patterns and colors throughout the property? True to the historical expertise our firm is known for, we weren’t going to copy those designs exactly but instead be inspired by them. The project became what we call Art Deco Fusion—a merger of Art Deco with modern, contemporary design.”

Ornate Design

The 11-story structure features opulent details like a 2-story decorative metal grille over the main entrance, granite and bluestone façade cladding, and a marble vaulted lobby. But one of the flourishes that most catches the eye of passersby are the building’s 700 window frames. Original to the 1931 building, they are made completely of bronze components—frames, sashes, stops and small decorative cord cleats once used in the open offices. Despite their age, these frames remained in remarkable shape.

A joint venture was comprised of Northern Equities Group and Lutz Real Estate Investments as they sought to revitalize the Albert Kahn Building and transform the property into retail spaces and 206 apartment units.

“The windows are a fine point to the building. The frames, which were original, were in phenomenal condition,” Elmore says. “The frames had never been painted, which is unusual for a building this age. The old chains and counterweights operated smoothly. Because the frames were in such good condition, replacement was never really a consideration for this historic building.”

While beautiful and ostensibly functional, the windows were found to be leaking substantial amounts of air. Weatherproofing at the perimeter was spotty, and only a single pane of glass blocked the external elements. The developers originally planned to just clean the bronze frames and replace broken glass with 1/4-inch monolithic glass when required, but the design team wanted a higher level of performance for residents.

“We needed to find a solution that would increase the thermal performance without replacing the frames,” Elmore says. “Allen Architectural Metals and Cunningham-Limp helped with the research.”

A Better Class of Glass

“We believed that a more appropriate solution for a residential conversion would be to restore the windows and make them operable by supplying an insulated glass option that the existing glazing pockets could accommodate,” recalls Kate Allen, president of Allen Architectural Metals, a firm specializing in metal casting and fabrication with particular expertise in restoration and historic preservation. “We asked the client if they would allow us to conduct market research on glass. Our hope was that we could find a product that gave them performance properties and that there might be a way to retrofit the historic windows. The client agreed and we reached out to the Association of Preservation Technology community to see if anyone had knowledge of a glass supplier that could help us meet these goals.”

The carbon to make the glazing products was paid off with reduced operating carbon in about one month. 

With conventional double glazing, there are two glass panes placed up to 20millimeters apart and the cavity between the panels is filled with either dry air or an inert gas, such as argon or krypton. The gas reduces heat transfer because of its lower thermal conductivity. The wider the gap between the panes, the lower the heat transfer. That means that the overall thickness of thermally efficient double glazing typically is about 24 millimeters, which is too thick for older frames, like the ones on the Albert Kahn Building.

Allen Architectural Metals was able to find a unique solution that utilizes vacuum glazing technology to provide the desired thermal performance in an ultra-thin unit that fits into the exiting frames and can maintain the aesthetics. The windows consist of an outer pane of low-emissivity glass and an inner pane of clear float. Rather than gas, there is a vacuum in between. The thin systems are made possible by a grid of micro-spacers used to separate two 3-millimeter pieces of glass. These micro-spacers are only slightly visible upon close inspection and disappear completely at 3-feet away. This solution delivered excellent thermal performance from a unit only fractionally as thick as a standard high-performance window.

“The glass is actually about the same thickness as the original frames, about a quarter inch,” Elmore says. “The outer pane has a low-E coating and the inner pane is clear. The space in between is a very, tiny sealed vacuum space. Replacing the glass offered increased thermal performance and comfort to the interior and allowed the heating and cooling equipment to not work as hard as it would have if the original glass had remained.”

In addition to being a major thermal performance upgrade, the new glass also more than doubled the Sound Transmission Class (STC) rating of the original glass to a value of 34. This is attractive to residents for the fact that it significantly dampens the city noise outside.

Retrofitting and performance upgrading existing buildings will be a key in the sustainability goals of most cities and companies, and the math and science support the results. In fact, the carbon to make the glazing products for this project was paid off with reduced operating carbon in about one month! (Learn more by contacting NSG Pilkington; the company has a one-hour AIA session related to carbon and retrofits.)  

Vacuum glazing technology provides the desired thermal performance for the windows in an ultra-thin unit that fit into the exiting frames and can maintain the aesthetics.

Past and Present

The project utilized the federal tax credit program for historic buildings, which is a program that ensures the rehabilitation of the building meets the Secretary of the Interior’s Standards for Rehabilitation. In keeping with that effort, the glass needed to be approved by the State Historic Preservation Office and National Park Service. Beyond providing the additional performance, the glass had to be shown to not interfere with views or create or deviate aesthetically from the original. It met the strict historic preservation requirements.

Today, the Albert Kahn Building offers contemporary, modern living spaces in a building that truly honors the legacy of one of Detroit’s greatest designers. It is considered by many to be an outstanding example of historic preservation and conversion to residential use.

“The project has been well received by the community and its occupants,” Elmore says. “The owner has received great feedback. In 2022, the project received a first-place award for the resident lobby design from the Detroit Design Awards.”

Oftentimes, the biggest hurdle facing restorations like this is bringing modern function to historic form. The technology that enabled the team to faithfully maintain the beautiful bronze window frames while bringing a superior level of thermal and acoustic performance to the building is a great example of how past and present can work together.

PHOTOS: courtesy NSG Pilkington

Retrofit Team

Architect, Interior Designer and Historic Consultant: Kraemer Design Group

Construction Manager: Cunningham-Limp

Ornamental Metal Fabricators: Allen Architectural Metals


Vacuum Glazing: Pilkington Spacia

About the Author

Jim Schneider, LEED AP
Jim Schneider, LEED AP, has worked in the design and construction industry for almost 20 years. He writes about architecture, sustainability and construction from Denver.

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