# Rooftop Mechanical Penthouses



## Aymanarafa (Mar 5, 2021)

We have an enclosed mechanical penthouse over the roof of a high rise office building. We comply with requirements in 1510.2 in matter of height and area limitations and are considering the penthouse as a portion of the story below and therefore have provided only one stair exit within the penthouse.
Is this considered an unoccupied space and we do not need to show travel distances to the exit? We are currently showing a common path of travel distance that is more than 100 feet. Do we have to reduce its size or can we consider the penthouse unoccupied and not show travel distances?


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## steveray (Mar 5, 2021)

What s in the mechanical penthouse?


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## Aymanarafa (Mar 5, 2021)

steveray said:


> What s in the mechanical penthouse?


Air handling units and mechanical equipment


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## classicT (Mar 5, 2021)

*1006.2.1 Egress Based on Occupant Load and Common Path of Egress Travel Distance*
Two exits or exit access doorways from any space shall be provided where the design occupant load or the common path of egress travel distance exceeds the values listed in Table 1006.2.1. The cumulative occupant load from adjacent rooms, areas or spaces shall be determined in accordance with Section 1004.2.

*Exceptions:*

The number of exits from foyers, lobbies, vestibules or similar spaces need not be based on cumulative occupant loads for areas discharging through such spaces, but the capacity of the exits from such spaces shall be based on applicable cumulative occupant loads.
Care suites in Group I-2 occupancies complying with Section 407.4.
*Unoccupied mechanical rooms and penthouses are not required to comply with the common path of egress travel distance measurement.*


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## klarenbeek (Mar 5, 2021)

Any equipment with refrigerants in the penthouse? If so, you may have created a machinery room as defined in chapter 11 of the IMC depending on quantities of refrigerant. If over 1000 sq. ft. you need two exit access doorways per IBC 1006.2.2, plus a whole bunch of other requirements per IMC chapter 11


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## Aymanarafa (Mar 5, 2021)

classicT said:


> *1006.2.1 Egress Based on Occupant Load and Common Path of Egress Travel Distance*
> Two exits or exit access doorways from any space shall be provided where the design occupant load or the common path of egress travel distance exceeds the values listed in Table 1006.2.1. The cumulative occupant load from adjacent rooms, areas or spaces shall be determined in accordance with Section 1004.2.
> 
> *Exceptions:*
> ...


Thanks for the feedback but I cannot find that exception on the IBC or FL code (where this project is located). Can you share which code references this? The codes I have only lists exception 1 & 2


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## Aymanarafa (Mar 5, 2021)

klarenbeek said:


> Any equipment with refrigerants in the penthouse? If so, you may have created a machinery room as defined in chapter 11 of the IMC depending on quantities of refrigerant. If over 1000 sq. ft. you need two exit access doorways per IBC 1006.2.2, plus a whole bunch of other requirements per IMC chapter 11


Thanks for the note. I will check that with the Mechanical Consultant.


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## classicT (Mar 8, 2021)

Aymanarafa said:


> Thanks for the feedback but I cannot find that exception on the IBC or FL code (where this project is located). Can you share which code references this? The codes I have only lists exception 1 & 2


Apologies... that may be a WA amendment.


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## mtlogcabin (Mar 8, 2021)

[BG] PENTHOUSE. An enclosed, *unoccupied rooftop structure* used for sheltering mechanical and electrical equipment, tanks, elevators and related machinery, and vertical shaft openings.


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## Aymanarafa (Mar 8, 2021)

classicT said:


> Apologies... that may be a WA amendment.


Thanks. I wish they would clarify that in the commentary at least but unfortunately it does not.


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## frankiepb98 (Sep 12, 2022)

Hi. I have the same issue right now. What was the final solution? Is there a section we can use to calculate the travel distance and common path different as this is unoccupied space? Thanks.


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## mtlogcabin (Sep 12, 2022)

An unoccupied roof is not subject to the common path of travel requirements or the travel distance requirements that an occupied roof would be. If the penthouse used to cover and protect the mechanical equipment from the elements is only accessed from the roof then it is definitely not an occupied roof.
A roof may have all kinds of obstacles that would hinder a clear and direct path to measure the travel distance if that where a requirements including a locked door.


1010.1.9.4 Locks and latches.
Locks and latches shall be permitted to prevent operation of doors where any of the following exist:
   6.    Doors serving roofs not intended to be occupied shall be permitted to be locked preventing entry to the building from the roof.


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