Exploring the Building Code - Intent
Understanding the intent of specific language of the building code can be confusing despite the efforts of architects and code officials to communicate in plain English. The problem is we all think and speak differently, so the intent can be lost in translation or it can become buried behind what we have to do and cover up the why we do it. The ICC realizes that understanding the intent can be critical in designing a complicated building and successfully reviewing it for code compliance.
With the above in mind the International Code Council has established several avenues for us to understand the intent. The first and most commonly used is the Commentary, but one avenue I’ve spoken about before that is often ignored is to request a code opinion. At M+A we maintain a library of code opinions for questions we have asked to not only help us better understand the intent of the code but also to share with clients and building departments. Sometimes we ask questions about sections of the code that seem straight forward, but the responses even though not always what we thought going into the conversation improved our understanding of the intent of the code. The following are a pair of examples where the plan language of the code appears kinda clear but the opinion fills in the missing intent.
We requested an opinion of 510.2, in this instance we were studying a horizontal podium building where the podium jogged. The plain English states that two buildings shall be considered distinct and separate buildings when separated by a 3 hour horizontal assembly. What was unclear is if the podium jogs do the number of levels begin at the lower of the horizontal plains of the fire rated assembly or do number of levels allowed jog with the podium as long as the maximum building height fell below per 510.2-6 below the maximum height of the most restrictive use and the number of levels above the podium never were greater than the number allowed by table 504.4. When we received our code opinion on this subject, the ICC pointed out the fundamental flaw, “Section 510.2 allows the building above and below the 3-hour horizontal assembly to be considered two separate buildings.” the intent is that the building above the podium is a separate and distinct building and that even though the podium jogged the total number of stories for that separate and distinct building could be greater than what is permitted by the code. In this instance the simple solution was to add a fire wall at the jog for the building above the podium so that we ended up with 3 buildings.
We requested an opinion of 1026.1, in this instance we were studying if by inserting a fire wall thus creating two distinct buildings automatically created a horizontal exit and therefore any exit paths through the firewall would need to comply with the code for horizontal exits per 1026. This section limits the number of exits that horizontal exits can be used for and puts in place requirements for areas of refuge. As stated in the ICC code opinion “openings in fire walls, used to subdivide a building for height/area limitations, are not mandated… to be regulated as horizontal exits unless the intent is to take advantage of the exit access travel distance limitations that would be otherwise permitted. Therefore, as long as the overall required exit access travel distance to an exit was always readily available in accordance with Table 1016.1, compliance with the further restrictions of Section 1026 for horizontal exits (exit restrictions, area of refuge, etc.) would not be required.”
Some might argue that the intent of the code in both instances is clear, aka in 1026.1 it says the horizontal exit is “serving as an exit in a means of egress” and 510.2 states that “a building shall be considered as separate and distinct… for the purpose of determining the limitation of number of stories.” But in both instances we or our partners in code enforcement have misinterpreted the intent of these sections.