Updated versions of the International Building Code are published every 3 years. On a new project, one of the first code restrictions to determine is the allowable building height, area, and number of stories.
Since 2000, the International Building Code has shown the allowable building height, area, and stories all in one table, 503. This one table also had to show the different factors used in determining the allowable height, area and stories which included the occupancy groups, construction types and whether it was protected or unprotected construction. Needless to say, this was a lot of information to have in one table and was not particularly user-friendly at first glance.
The new 2015 version of the IBC separates this information into three different tables (see below), but the technical application is unchanged. The three tables also incorporate sprinkler increases for the height and areas which were calculated separately in earlier versions of the code. I prefer the new 3 table system and find it easier to use and calculate the area/height/story increases. However, it can be argued that it is more difficult to quickly determine the tradeoffs when going to a more or less restrictive construction type because you have to look in three different places.
