Finger Lakes Building Officials, Inc.

An Affiliated Member of the New York State Building Officials Conference

May 13, 2003

RE: Alteration of one-family dwelling to two-family dwelling
Stair configuration & tenant separation

This is in response to your questions regarding the alteration of a one-family dwelling to create a two-family dwelling, the configuration of the stair to access the upper dwelling and the requirement for a dwelling unit separation, a one-hour fire-resistive rated floor/ceiling assembly. You have correctly stated that the project is an alteration regulated by section AJ501 of the Residential Code of New York State (RCNYS).

Section AJ501.1, Newly constructed elements, requires that all newly constructed elements, components and systems shall comply with the requirements of the RCNYS. You ask if a proposed partially enclosed stair, protected from the weather, can be considered an interior stair for compliance with section R312.1.1 exception so that the stair can land at the top without a landing and with an in-swinging door. It is our opinion that the stair enclosure you describe does not meet the requirements for enclosure as an interior stair.

With respect to the dwelling unit separation, section AJ501.2, Nonconformities, requires that the work shall not ... create nonconformity with those requirements which did not previously exist. It is our opinion that the dwelling unit separation is required in accordance with section R321.1.

This advisory opinion is rendered based upon the information provided. Administration and enforcement of the code are within the jurisdiction of the local authority. If you have questions regarding this advisory, please call me at (518) 474-4073.

Sincerely,

Cheryl A. Fischer, P.E.
Assistant Director for Code Interpretation
Codes Division
Al03-106

Finger Lakes Building Officials Association, Inc.
3100 Atlantic Ave.
Penfield, NY 14526