Code and Legal Topics
March 2002

Exit Requirements

The intent of the article is to convey an understanding of the Uniform Building Code's exiting requirements and its impact in cases where existing space is being subdivided. It is very possible that the division of space may not be economically sensible to consider due to restrictive exiting rules in the code. Particular attention should be given to subdividing retail spaces where the back exterior wall has been built on the property line and to office suites in multi-tenant buildings. In cases where more than one exit is required it is sometimes not possible to provide a potential sublessee with these "required exits".

The following table (Table 10-A of the California Building Code) is used by every building department in the state when determining the number of "required exits" for a space. The number of company employees is meaningless to an exiting calculation. The table shown is abridged, reflecting the most common occupancies.

Occupant Load

Determine the use that the tenant will using the space for. Locate that use in the left column of the table. Divide the area of the space by the load factor in the right column. If the product is equal to or greater than the figure in the center column (Occupant Load) then two exits will be required.

Occupancy Type How the space is used Two exits required when occupant load equals or exceeds: Occupant Load Factor Churches and auditoriums 50 7 Conference and exhibit rooms 50 15 Classrooms 50 20 Manufacturing areas 30 200 Retail 30 50 Warehouse 30 500 Office 30 100

Example:

So your client, Entropydotcom, wants to sublet 4,000 s.f. of his 7,500 s.f. office space which presently has two exits. How many exits will be required when the space is subdivided? Answer: 4.

Let's calculate the occupant load for Entropydotcom's sublessee.

They are going to sublet 4,000 s.f. to Startup.Com who will use it as office space; therefore the Occupancy Type is Office. The Occupant Load is calculated by dividing the area of 4,000 square feet by the Occupant Load Factor, in this case 100. The product is 40 (occupants) which exceeds the load threshold for a single exit; so this 4,000 s.f. sublet space will need two exits.

The remaining area retained by Entropydotcom is 3,500 s.f., which when divided by the load factor of 100, yields an occupant load of 35 and therefore the requires two exits as well. So the entire 7,500 s.f. space, once adequately served by two exits, when subdivided, requires four.

'The Problem':

In cases where two exits are required "they shall be placed a distance apart equal to not less than one half of the longest diagonal length of the space; measured in a straight line". In the case given above this code section could be a deal buster if the exits can't be positioned as required due to the building's physical characteristics. Frequently in these cases the only solution is that of constructing a corridor (expensive and chewing up a lot of space) which may be so undesirable and/or cost prohibitive that it would not be feasible to do.

Exiting issues should be addressed immediately when considering subdivision of space since there could be a significant cost impact to the parties. Chapter 10 of the building code (Means of Egress) is much more complex than conveyed here and most cities require the participation of a licensed architect in a construction project having significant exiting issues.

TiCon can provide architectural services for design/build projects or refer an architect as a consultant.