Begging The Question

The title refers to one of the classic logistical fallacies, where an argument is made that assumes its conclusion. The specific instance of this fallacy that often bothers me concerns code updates and existing buildings. Every time a code – for example, the New York City Building Code, the IBC that it is mostly based on, the ASCE 7 loading criteria, or the various material specifications – is updated, some group of buildings designed under an older version of the code no longer meets the technical requirements of that code. People often say, in shorthand, that the old buildings “no longer meet code” but that’s usually not true. The NYC Building Code, like the IBC and its other derivatives all grandfather buildings designed under previous codes. Buildings are so grandfathered literally “meet code” in that manner.

So far, this is a linguistic annoyance but no worse. The real problem comes with the question of when a building has to be upgraded to meet code. The New York City Department of Buildings has published various thresholds that require upgrades, in the building code and elsewhere, that should clarify that issue. To use one example, §28-101.4.5 of the Administrative Code, with some nice examples in Buildings Bulletin 2016-012, requires that an alteration be designed as if it were a new building (i.e., meet current code for technical provisions) if the alteration increases the floor area by more than 110%. That percentage is calculated by comparing the proposed post-alteration floor area with the floor area that remains after removals. If you remove and replace a floor, it counts as new floor area; if you remove and replace more than 55% of the existing floor area, you will exceed the 110% threshold.

I have seen people argue that since exceeding the 110% threshold will require a building to have upgraded structure, that they should upgrade the structure, including in cases where they only reason they are exceeding the 110% threshold is that they chose to upgrade the structure. They are upgrading because they assume they will have to but the only reason they have to is that they made the assumption. Classic example of begging the question. Note that I have no problem with someone choosing to upgrade because they want to, regardless of code issues, but that’s not what happened in those cases.

Another reasonably common example is someone saying that a masonry wall doesn’t meet current code (it’s unreinforced, for example) and so it has to be replaced, but it’s the replacement that triggers the requirement for meeting current code technical provisions.

One way to avoid this trap is to recognize codes for what they are: the current manifestation of a long evolution of thinking on a topic that will evolve more in the future. Yes, we can and should follow code provisions, but they are not unalterable truths, as shown by the fact that they change over time. And a code written in 2024 can legally apply to a building constructed in 1910, but it can’t have been a factor in that building’s design and so has to be used with some care and thought in that building’s analysis.

The structural cast-iron facade of the Houghwout Building, in the photo above, does not meet the technical provisions of current code for multiple reasons. It’s also grandfathered, per current code, and has been performing just fine for over 160 years.