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This help desk is a free resource intended for discussion purposes only. Neither BOMA, its chapters, affiliates, or Extreme Measures Inc.® are responsible for the information, comments or opinions expressed herein. For complete information, refer to the official publications of the standards themselves.

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Exclusive Fire Exit Stair Added for New Rooftop Deck

Ian O'Neill
October 6, 2020

We own a mixed-use two (2) story building composed of ground floor retail (3 units) and second floor office (1 unit). The second-floor office covers approximately 50% of the retail below with the balance of the retail just having a roof above – not office. Since this roof is at the same elevation as the office finish floor, the office tenant often uses the roof as a deck. We are planning to turn the roof into a legitimized and rentable rooftop deck which will require a fire stair exit to penetrate the deck and exit the back of the retail below. Since the stair is exclusive to the upstairs single tenant office for fire exit, can it be included in that office's RSF? Also, would the stair floor area be counted or removed from the retail space below?

David Fingret
Extreme Measures Inc.
October 7, 2020

Hi Ian,

Since the building you describe is comprised of more than 50% retail space, the BOMA Standards would recommend applying the BOMA 2010 Retail Standard to the entire building, including the office area on the second floor. As such, none of the exterior areas would be considered Gross Leasable Area, and neither would the stairs. The rooftop deck however, could be an Ancillary Area.

If you were to measure the building according to the BOMA Office 2017 Standard, the Finished Rooftop Terrace would be considered rentable area as it would be a separately disclosed Occupant Area. The required stair however, would be a Major Vertical Penetration and therefore, excluded from the Rentable Area on the second floor. On the ground floor however, the area of the stair would be allocated to your office tenant as Rentable Area, using Inter-Building Service Area calculations.


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