BDG architecture design

Working in New York

New York - some useful space codes to assist with planning

This is an extract from work we have done using Vocon (our US partners to assist with space codes/regs) to understand max occupany levels for offices in NY. Use this for guidance however always check with Vocon (John Workley is their technical guru)

From: John Workley 
Sent: Monday, June 06, 2011 11:13 AM

maximum density of staff in offices in NYC (occupancy)

Occupancy calculations (YES) equal 100ft2 per person to establish the Maximum Calculated occupancy load for the tenant space and floor

Defined in Multi - tenant floors (with corridors to egress points) or a single tenant floor (corridors to egress - optional)

With the small footprints in NYC they usually are laid out as single tenant floors.

Two ways to establish the Maximum occupancy for designing the egress stair components of the building.

Maximum Calculated occupancy calculated as noted above

And Counted Actual occupancy  (we call buts in seats) or chair count, the number of chairs = occupant load  (this is for small cubical and call centers of 6x6 workstations)

Then whichever is higher is used to calculate if the egress width designed for the building supports the occupant load (should always exceed).

i.e.  22,000 sqft tenant space / 100sqft per person = 220 occupants  (and counted seats = 219)    Use 220 occupants


Means of escape (exiting)

Exiting Widths for stairs and exit doors are calculated as follows:

Occupancy x multiplier of .3 for stairs =  66” minimum width for egress stairs   (standard is 44” width minimum and two stair towers = 88”) so we comply.

Occupancy x multiplier of .2 for doors = 44” minimum width for egress doors   (industry standard is 36” door and two stair towers = 72”) so we comply. 

Note doors may be as small as 32” in width minimum to meet the accessibility standards – however the 36” door is usually standard installed.

Washrooms on a ratio  Rest room calculations:

Water Closest fixtures: are 1/50 occupants +1 fixture =   for every 50 occupants = 1 fixture   i.e.:  220/50= 4.4 +1 = 5 minimum required

Water closets and Urinal fixtures all equal one fixture  (however urinals cannot be more than 50% of required)

Lavatory fixtures:  are 1/80 occupants +1 fixture =       i.e.   220/80= 2.75 +1 = 4 fixtures  (this is rounded up, too)

Water cooler drinking fountains = 1/100 occupants    i.e.:  220 = three 3 fountains  (required to be accessible High/low fixtures).

1 janitor closet (mop sink) is required per floor

Air and cooling supply

I will need to consult our engineers for general guidelines for their design parameters.

John C. Workley
Director of Architecture
M (216) 570-3070