Common Path of Travel

Q: How do you calculate the Common Path of Travel and/or Total Travel Distance for a multi tenant suite when the space planning for the individual rooms has not been completed? For each tenant, I’m assuming to find the mid-point in the vacant tenant space and equal out the “travel distance” to the tenants’ 2 exit doors? There is a common area vesitbule and common corridor that is rated. One of the tenants fits the single exit rule, so I believe that tenant would only have a “total travel” and no “common path”? Thank you!

A: You certainly have asked a very good question. The quick and easy answer is: ‘You do the best that you can’, which is a bit of a cop-out. But, to be sure, you make a very good point, as travel distance is measured around obstructions, according to section 7.6.2 in NFPA 101 Life Safety Code (2000 edition). Take a look at the Annex section A-7.6.2, which says:

“The natural exit path (path of travel) will be influenced by the contents and occupancy of the building. Furniture, fixtures, machinery, or storage can serve to increase the length of travel. It is a god practice in building design to recognize the influence of contents and occupancy by spacing exits for a completely open floor area at closer intervals than is required, thus reducing the hazard of excessive travel distances due to the introduction of furniture, fixtures, machinery, or storage and minimizing the possibility of violating the travel distance requirements of this Code.”

While the Annex section is not an enforceable section of the LSC, it certainly is an explanatory reference guide that authorities having jurisdiction (AHJ) frequently use to make interpretations of the code.