What is a Building Code? What does it do? Most would agree that it is a document filled with a series of rules that have been put in place to make buildings safe for the public’s interest.
How does it do this? By communicating these rules to the people responsible for creating our buildings and making them safe – architects, engineers, builders, building officials etc. Codes organize these rules into divisions, sections, categories and apply them to all buildings. This works quite effortlessly when those buildings fit into the perfectly prescribed boxes defined in the Code.
But all buildings are not created equal. Buildings are like snowflakes, every one is unique. When a building does not fit the conveniently crafted molds and categories of the Building Code, you’re left wondering what rules to apply to it and how they apply. Remember the Tupperware Shape-O Toy? The plastic red and blue sphere with yellow pieces, each piece fitting only through one particular hole? Now picture that sphere as the earth and every yellow piece a building. Everything fit perfectly until the Santiago Calatravas, Frank Gehrys, and Bjarke Ingels of the world came along. Like the Shape-O Toy, the Building Code can only have a finite number of categories or ‘holes’ for which a building can fit. Apparently, whether you’re a toddler or a seasoned engineer, we all have the same problems!
I’ve written previously about the Nuances of Occupancy here where I talk about how to decipher between major and subsidiary occupancies, but what if you’re not even sure what occupancy class or group you fit into? We are not discussing “Special and Unusual Structures” as explained in Article 3.2.2.2. Examples of these types of structures are provided in the Notes as grain elevators, refineries, and towers. The types of structures and buildings described in this article look like a lot of the buildings we see everyday but are sometimes difficult to categorize because of their use. As we know from Table 3.1.2.1., the 13 occupancy classes are categorized first into groups, A, B, C, etc., then divisions, 1, 2, 3, etc. Conveniently, the Code provides examples for all the major occupancy classifications as a reference. This is described in the Notes to Part 3 (A-3.1.2.1.(1)). Users of the Code frequently reference this list to help determine how their building fits into one of the occupancies. To stay current and keep up with changing trends in building types and uses, the list of major occupancies in A-3.1.2.1.(1) has seen some additions, deletions, and edits over the past few Code editions including the creation of a new Division in 2012 under Group B, Care, Treatment and Detention Occupancies. Still, this list cannot possibly encompass every conceivable occupancy. Similarly, Table 3.1.17.1. has not changed since the first BC Building Code in 1980. This leaves us questioning what occupancy class some of today’s buildings and modern day uses should be classified under.
When the occupancy class of a building is not clear, an interpretation needs to be made. This is often done by the Authority Having Jurisdiction or the Coordinating Registered Professional or by both of them working together to come to an understanding.
If there is ambiguity in occupancy the AHJ will sometimes request an Alternative Solution or similar report to provide rationale on why a certain building should be classified as a particular major occupancy and not another. Some contemporary examples are craft breweries and distilleries, cannabis cultivation facilities, and data centres. For example, in the BC Building Code, distilleries are listed in A-3.1.2.1.(1) as F1, high-hazard industrial occupancies, however, this occupancy classification was likely established prior to the modernization of provincial liquor laws that allowed small craft distilleries to flourish. The high-hazard classification is well suited to large scale distilleries that operate large stills and handle extremely large quantities of flammable liquids (ethanol) but with the growing popularity of small-scale craft distilleries, assigning an occupancy of F1 is inappropriate and imposes too many restrictions on what would commonly be considered a medium or low fire risk.
As the way we use our buildings changes and new occupancies arise, the approach of using Alternative Solutions to justify a certain occupancy becomes cumbersome. In those instances where Building Codes and Fire Codes do not provide sufficient guidance or direction on topics such as choosing the appropriate occupancy, design professionals, engineers, and building officials must work together to make reasonable and rational judgments that help maintain the intent of the Codes yet avoid onerous construction.
