A report of an apartment fire in a three story 15 unit sprinklered building in Everett, Washington. The fire started on a balcony and went unchecked until the interior sprinklers activated. One person was injured and about 10 residents were displaced. [heraldnet.com]
This fire started outside on a deck, where there are no sprinklers,” Hynes said. “The sprinklers inside didn’t activate until the fire burned through the wall and ceiling and into the interior of the apartment.”
There is an exception for placing sprinklers on exterior porches and balconies in NFPA 13R however, I’m pretty sure we’ve been forced to protect them before because of a requirement in IBC. I’ll do some asking around, and check the code.
Update: Balcony protection is required in IBC. I had a conversation with a PM with some experience in residential and verified in the book (section 903.3.1.2.1).