Why some NYC sidewalks have small glass domes

You probably have walked by or on top of them and never even noticed. But glass dome sidewalks, commonly called vault lights, are a unique part of New York City's history.

The vault lights were widespread in manufacturing districts like SoHo and TriBeCa before electricity. They provided natural light into the basements below where people worked handling coal and other deliveries.

These are some of the last vestiges of the 19th-century industrial revolution. Once they are severely deteriorated, building owners can either restore them, which is expensive, or cover them with steel plates. However, building owners have to go through a public hearing in front of the city's Landmarks Preservation Commission to get approval to cover the glass sidewalks.

Now, the commission wants to change that rule and forego the public hearing so that members can decide if a glass sidewalk is deteriorated enough to warrant covering.

Historic Districts Council and others oppose that idea. Executive Director Simeon Bankoff said the proposed rule change should be withdrawn because it takes public transparency out of the process.

"The proposed rules only authorize staff to allow the removal of highly deteriorated vault lights," the Landmarks Preservation Commission said in a statement. "Any other proposal to remove vault lights that are not highly deteriorated would be decided by the commission at a public hearing."