Some history first.
After the Plymouth Meeting Mall fire in 1970, the various code communities took action to change the codes to address what was at the time a fairly new type of design. The fire started in one tenant space and then progressed out, into the mall and toward the large anchor store at the end. There was no requirement for alarms, sprinklers, standpipes or other fire safety systems that today we take for granted. They basically threw the book at malls adding everything that could be thought of as a way to make these facilities safer - the typical knee-jerk reaction. Interestingly, the anchor store had a type of a sprinkler system at the mall entrance and the fire stopped its progression as soon as it hit that water. To be sure, this was not willy-nilly. The Board for the Coordination of the Model Codes (BCMC) deliberated and decided on a position to present to the three code groups (and NFPA). Of course, each group decided on something slightly different.
Over the years, BOCA had slowly whittled a number of the requirements away from the mall provisions. Smoke control would be based on the atrium provisions since that is when a "hole-in the floor" becomes a problem. Anchors could be things besides mercantile since theaters and even hotels were being added to malls. Fires in facilities built under those "altered" provisions substantiated the fact that the main thing was sprinklers. After that it was all about warning folks and then assisting the fire departments in doing their tasks.
When the three codes unified, there was plenty of compromise. Smoke control control for one-story malls was back in based on the fact that two out of three of the legacy organizations had it in there. Somehow voice alarms was added - above the simple fire alarm provisions in two of the three. Sprinklers and standpipes were the same. Then, after the I-codes were published, the smoke control section started to change to reflect what the BOCA people had been telling us - smoke in one-story malls is not manageable. Smoke in two story spaces is questionable and difficult at best to manage. It takes a height of at least 30-60 feet to be able to manage smoke to some degree. Even the Life Safety Code does not require smoke control for one-story malls.
As for anchors; the main reason to be an anchor is to have independent control of the entrances to the facility, irrespective of the mall's operating hours. An anchor can have midnight madness sales long after the mall is closed. Because of that, its exits must be counted separately from those in the mall. Also, as a result of the separate ownership, there must be a rated separation between the mall and the anchor. Under the BOCA this was a fire wall (with its structural Independence and all that). Under Southern it wasn't clear what it was. Under UBC it was simply a rated wall. The compromise was to use the rated wall in most cases.
If the anchor is no more than three-stories, then it could be a tenant space except for the separate ownership concern. Anything with taller expectations needs to be an anchor.
<<< btw: Riddle me this Batman: Why is a three-story 85,000 SF per story department store of unrated construction OK as long as it's attached to the mall (assuming it has all the sprinklers and bells included); but, if the mall is demolished it is now too big? Hmmm? >>>
