For nearly 20 years, the $500 million art collection of the late developer Sheldon Solow has been behind closed doors, its masterpieces sealed off on the ground floor of a Midtown Manhattan office building. People could catch glimpses through windows of the eponymous Solow Building, but going inside the galleries was out of the question.

That will soon change, as Solow’s family plans to renovate and expand the Solow Art and Architecture Gallery ahead of a full public opening in 2023.

Its blue-chip collection is said to include works by the likes of Henri Matisse, Joan Miró, Jean-Michel Basquiat, Jean Dubuffet, Alberto Giacometti, Francis Bacon, Franz Kline, Vincent van Gogh, Amedeo Modigliani, and Henry Moore.

“I am proud to say that we will be displaying the artwork to the public once our remodeling has finished,” Hayden Soloviev, one of Solow’s grandsons, and the vice chairman of the Soloviev Group, told the New York Post.

He further confirmed that the gallery will be opening its doors, not just letting passersby peek in from the street.

The Solow Building at 9 West 57th street, developed by Sheldon Solow, opened in 1974. Photo by John Lamparski/Getty Images.

Solow died in November 2020, at age 92. Soon after, his wife of 48 years, artist Mia Fonssagrives-Solow, announced her intention to welcome the public to his collection.

Now, the Solow Foundation plans to expand its galleries to the tower’s West 58th Street side with construction due to begin soon. Allowing public access to the space will help silence criticism of the foundation, which received tax-exempt status as a private museum with a public gallery.

Such institutions met with the opprobrium of the Senate Finance Committee in 2016, with chairman Orrin Hatch (R-Utah) writing in a letter that “this area of our tax code is ripe for exploitation.”

A 2018 Crain’s New York Business report confirmed that Solow’s foundation still received federal tax breaks, despite a lack of public visiting hours.

Since 2017, an unofficial Solow Foundation website, created by an art lover and activist named Ethan Arnheim, has called attention to the gallery’s tax status and lack of visiting hours.

There have also been high-profile, big-ticket sales of works from the Solow collection in recent years, including Sandro Botticelli’s Young Man Holding a Roundel, which became the second-most expensive Old Master painting ever to hit the auction block with a $92.2 million sale at Sotheby’s last January.