This is addressed in the Multiple Dwelling Law. The AG's guide
summarizes this requirement:
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ENTRANCE DOOR LOCKS AND INTERCOMS
Multiple dwellings which were built or converted to such use after
January 1, 1968 must have automatic self-closing and self-locking
doors at all entrances. These doors must be kept locked at all times
-- except when an attendant is on duty.
If this type of building contains eight or more apartments it must
also have a two-way voice intercom system from each apartment to the
front door and tenants must be able to "buzz" open the entrance door
for visitors.
Multiple dwellings built or converted to such use prior to January 1,
1968 also must have self-locking doors and a two-way intercom system
if requested by a majority of the tenants. Landlords may recover from
tenants the cost of providing this equipment. (Multiple Dwelling Law
§50-a)
****
ALL of your rights as a tenant under the city and state landlord-
tenant laws (excluding the rent laws) are laid out in this guide. It
is posted on the AG's page (
http://www.oag.state.ny.us/realestate/
tenants_rights_guide.html) and at the Rent Guidelines Board (http://
www.housingnyc.com/html/resources/attygenguide.html#17).
See the group resource page for quick access to those links.