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By: Ivy Yuan 


Rooftop outdoor spaces command huge premiums in the ferociously competitive real estate scene and have been increasingly used to woo tenants and boost rents. If eight conditions are met, the conversion of an existing building’s unoccupied rooftop to a public terrace can be filed as an Alteration Type 2 (Alt-2) without requiring a new or amended Certificate of Occupancy.

First, the proposed new public terrace must be accessory to a principal use within the building. For example, if a building is residential, the terrace must only be an addition for the residents, not for the building to use as a commercial space. It also means thatuse of the space does not involve excessive noise, vibration or other nuisances. Secondly, the maximum occupant load of the proposed public terrace cannot exceed 74 persons, based on floor area per occupant, in accordance with BC Table 1004.1.1 of the 2014 Building Code.  As a result, a Place of Assembly Certificate of Operation is not required per the 2014 NYC Construction Codes. Increased occupant load may be permitted provided it complies with Section BC 1004.2 and is posted on a sign established by the registered design professional.

The third condition states that the conversion of the roof to a public terrace will not need additional required exits. Per Section BC 1004.8, occupied terraces are treated as outdoor areas with respect to means of egress requirements. If occupants on the terrace have to pass through the interior floor before reaching the exit, the means of egress of the interior floor must be based on the sum of the interior and outdoor occupant loads. If there is an independent and direct means of egress to the outdoor area that is independent of the exit for the interior space, the occupant loads can be calculated separately.

The conversion of the roof to a public terrace should also not propose structural alterations to increase the live loads capacity that would require revisions to the live loads stated on the Certificate of Occupancy. Additionally, the fifth conditions states that the maximum occupant load permitted on the public terrace should not exceed 30 people in one exit stairway for residential occupancies where the occupants are primarily permanent. If the proposed public terrace is to hold more than 30 people, additional exit stairways must be provided and a new building or Alt-1 filing, as well as a new or amended Certificate of Occupancy, is required.

A new building or an Alt-1 filing, as well as a new or amended Certificate of Occupancy, will also be required if the public terrace floor area is subject to enclosure requirements in the Zoning Resolution. In certain zoning districts (C1-C8 and M1-M3), the use of a roof may be subject to enclosure requirements; however, roofs intended to be passive recreation spaces are not. The sixth condition states that the rooftop needs to be indicated on the construction documents associated with the Alt-2 filing, and the purpose of the roof will decide if it will be considered floor area.

The seventh condition requires structural plans for the rooftop to be included in the construction documents submitted for the Alt-2 filing as described in Section BC 107.7. A new or amended Certificate of Occupancy is not required to include the updated live load figures. Lastly, the construction documents must also include means of egress plans for the roof per Section BC 107.5 and should comply with applicable provisions of BC Chapter 11, as required by Section BC 1101.3.

In conclusion, owners, property managers, residential boards or building occupants that wish to convert the roofs of their existing buildings into public terraces should pay special consideration to egress, loading, and other safety requirements such as parapet and guardrail heights. Rooftops and terraces that are open to building occupants must be designed in accordance with NYC Construction Codes and must comply with the Zoning Resolution.


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