Lady Seton converted house

Here at Untapped Cities, we’ve written about many unique architectural conversions in New York City, from churches to psychiatric asylums to synagogues. But today, we’re showing you the transformation of homes from mansions to tenement houses. 

1. Cartier, 651-653 Fifth Avenue, the Plant Mansion

The reason behind Cartier‘s chosen flagship store is a popular one. Cartier itself produced a documentary on the “worst trade ever.” While told with varying levels of detail and perhaps, exaggeration, the store is also known as the “House that Pearls Bought.”


When wealthy railroad tycoon heir Morton Plant left New York for a short stay in the country, his younger wife approached Pierre Cartier. Mrs. Morton Plant wanted Cartier’s latest piece on exhibit at their store a few blocks above her own 1905 mansion. Her proposal was straightforward swap: pearls for a Fifth Avenue mansion. Mr. Plant returned to find he now owned a beautiful pearl necklace and Cartier now worked on opening shop at a beautiful Beaux-Arts mansion. The Times has since thrown some cold water on this story but consensus remains, one way or another, pearls are involved.

The building is currently under renovation and slated for a 2016 reopen. Renovation efforts are focused on modernizing many of the basic code requirements, such as heat and air-conditioning, but also exposing more of the original detailing. Beyer, Blinder and Belle, the architectural firm known for preservation work on Grand Central Terminal, the Empire State Building, and Ellis Island (to name just a few) are leveling the entrance floor, more in line with the original design and expanding the second floor event area previously used by the Plants as their expansive sitting room, among other enhancements.