Unless specifically specified by the shipper that they require a signature, it is entirely left up to the driver whether the package is left at the house/building. In most cases, apartment buildings do not follow this rule. The only exception to the above is if the shipper authorizes a release; meaning that UPS leaves it at the residence no matter what, apartments included.
So, if you talk to your driver and get to know them, you can tell them to leave it. Or you can call UPS and tell them to leave it, as well. 1-800-PICK-UPS (1-800-742-5877)
\Used to work for UPS for many years