DOB proposes new sign rules for basement and cellar ADU entrances

What happened

The New York City Department of Buildings (DOB) has proposed changing the sign rules for ancillary dwelling units (ADUs) in basements and cellars. The notice ran in The City Record on October 2, 2026. The change amends section 105-08 of Title 1 of the Rules of the City of New York. DOB says the rule came out of required consultations with the Fire Department and the Office of Emergency Management. Its purpose is to help the Fire Department find ADU entrances in an emergency.

The rule applies where an eligible basement or cellar ADU entrance is not apparent from the street and there is no existing identification sign. In that case, a permanent sign with red letters on a white background must be mounted on or near the primary dwelling. It must be placed where it is plainly visible from the public street or the fire apparatus access road. The sign must be at least 11 inches tall by 17 inches wide. Each letter and number must be at least 4 inches tall, with a stroke width of at least half an inch. The first row must read "ADU-BAS" for a basement unit or "ADU-CEL" for a cellar unit. The second row must read "EXP - 1", "EXP - 2", "EXP - 3" or "EXP - 4" to show which side of the building has the entrance.

Exposure 1 is the side facing the street where the building's official address is assigned. Exposure 2 is to the left and Exposure 4 is to the right when you stand in the street facing Exposure 1. Exposure 3 is the side opposite Exposure 1. The current rule calls for a directional sign with red letters at least 5 inches tall, stating in sentence form which exposure the entrance is on. Under the proposal, an existing sign that is in place on the rule's effective date and complies with the old rule does not have to be replaced.

DOB will hold an online public hearing at 11:00 AM on November 4, 2026. Comments are due by that date. People who want to speak should sign up by emailing [email protected] by October 28, 2026. Requests for disability accommodations are due by October 21, 2026. The Mayor's Office of Operations certified that the rule has no cure period because it does not create a violation or change penalties.