second floor occupant load calculation.pdfMiller, Chuck
From: Miller, Chuck
Sent: Wednesday, March 15, 2017 11:17 AM
To: 'Brad Barbee'
Subject: RE: HomeStreet Bank Edmonds (PRE20170003)
Good morning,
First, we have to get out of IBC Chapter 3... at least for determining the occupant load of a space. Occupant loads are
always determined by the use or `function of space' of the actual spaces, not by the occupancy classification.
IBC Chapter 3 is used to determine the occupancy classification of structures or portions of structures, not the occupant
load. That determination is then `carried over' to Chapter 5 to determine the `allowable heights and areas' and `required
separation of occupancies' and to Chapter 9 for the `automatic fire sprinkler system' requirements for each of the
classified occupancies. Once that is done, most of the `heavy -lifting' of Chapter 3 has been completed.
IBC Sections 303.1.1 and 303.1.2 both regard the classification of the occupancy, not the use or `function of space' of the
area. Both of those sections note the use of a building, tenant space, rooms, or spaces for assembly use with occupant
loads less than 50. To apply the sections, the occupant load must first be determined based on the `function of space' as
an assembly use or purpose with the applicable `occupant load factor' per IBC Table 1004.1.2. Those meeting the
conditional language of the referenced sections are then relieved of having to meet the requirements of `Assembly Group
A' occupancy classifications found in the rest of the IBC for those smaller spaces. This eliminates the need to separate a
smaller conference room from the rest of an office space with fire -resistance rated construction per IBC Table 508.4 or of
having to install an automatic fire sprinkler system in the whole building because of the small space. The same
methodology is more commonly applied to smaller restaurants where, when combined with the occupants of the kitchen
and storage areas, the smaller number of diners present do not justify the requirements of larger `assembly classifications'.
Feel free to call if you would like to discuss this more. (I also recommend reading the IBC commentary regarding IBC
Sections 303.1.1 and 303.1.2 and IBC Table 1004.1.2 for additional information)
From: Brad Barbee [ma iIto: Brad. Barbee@MG2.com]
Sent: Monday, March 13, 2017 4:12 PM
To: Miller, Chuck
Cc: Elisha Person; Fred Lawson II
Subject: HomeStreet Bank Edmonds (PRE20170003)
Good afternoon Chuck, thank you for taking time to meet with our HomeStreet Bank team last Thursday. During our
meeting we touched on the occupant load calculations for Lobby/Reception, Breakrooms and Conference Rooms and I
wanted to follow up that conversation with you.
IBC 2015 Chapter 3 states the following with regards to smaller assembly spaces that are used as accessory spaces to
another occupancy type:
303.1.1 Small buildings and tenant spaces.
A building or tenant space used for assembly purposes vJth an occupant load of less thar
classified as a Group B occupancy.
303.1.2 Small assembly spaces.
The follovving rooms and spaces shall not be classified as Assembly occupancies:
1. A room or space used for assembly purposes ;vith an occupant load of less than 50 pe
another occupancy shall be classified as a Group B occupancy or as part of that occupan
2. A room or space used for assembly purposes that is less than 750 square feet (70 m2)
to another occupancy shall be classified as a Group B occupancy or as part of that occup
Based on those sections we typically do not calculate breakrooms, conference rooms or lobby/reception spaces as
assembly as long as they are under 750 SF or have an occupant load under 50 persons. I would like to get your feedback
to sections 303.1.1 and 303.1.2.
We are concerned if we design our 2nd floor tenant space for one exit with an occupant load under 29 persons that any
future office tenant build out will have issues with their occupant load and egress if it includes spaces that may be
viewed as "assembly".
Please feel free to give me a call to discuss or let me know if you have any questions.
Thanks,
Brad
Brad Barbee
Associate
MG2
1101 Second Ave, Ste 100 / Seattle, WA 98101
Direct 206-962-6639 / Ma 206-962-6500
MG2.com
Disclaimer: The contents of this e-mail and any attachment(s) are confidential and the property of MG2.
2