Info 202 Fall 2011

When one thinks of floors inside of a building, a simple numbering system seems fairly obvious. Organizing and labeling floors by number satisfies the reasonable objective of helping people quickly understand the physical and vertical relationships between each story. In reality, while most buildings follow this generic organizing system, confusing oddities can quickly emerge.

This article in the New York Times describes a longtime trend for Manhattan high-rises to overstate their stories. While sitting in Central Park, one 67th floor homeowner in the AOL Time Warner building counted the floors of his building and realized that his apartment was actually on the 56th floor. It turns out this has become fairly common with buildings in New York City, where a higher “floor” of a property can increase its value and prestige. Many in the real estate world credit Donald Trump as the pioneer of this strategy. After he built Trump Tower in the 1980s, Trump decided to start the residential floors at 30, reasoning that they were above 19 levels of commercial property plus an atrium.

The NYC Department of Buildings does not require that floors are numbered in any sequence. Floor numbering systems have thus strayed from one of their original guiding principles: one can no longer reliably measure vertical height based on the floor number. This also makes comparing buildings more difficult – for example, the article mentions the 716-foot, 78-story Metropolitan Tower, which happens to sit right next to the 757-foot, 60-story Carnegie Hall Tower.

This exemplifies a broader trend of how arbitrary floor numbering systems can be. In most Western cultures, buildings skip the 13th floor because 13 is an unlucky number. Similarly, in China, buildings skip the 4th floor because of the number 4’s phonetic similarity in most dialects to the word for death. In some cases, buildings skip every floor with a 4 in it (14, 24, 40-49, and so on).

We also run into the vocabulary problem all the time with floor labels. In the US, 1 is generally regarded as the ground floor of a building. In Europe, the ground floor is 0, and the next story up is 1. Many buildings label the ground floor as G, but this is not always the case. In my residential building, there are buttons for G and P. Most visitors assume that G is for Ground and P is for Parking, but in actuality G is for Garage and P is for Plaza. South Hall’s elevator has floors labeled as G, 1, 2, and 3. As it turns out, “Ground” at South Hall is actually the basement.

In other words, floor numbering is completely unreliable and inconsistent. Personally, I find it both interesting and funny that floor numbers don’t really tell you as much as one might expect. It’s a spatial cognition (and user interface) issue worth thinking about when it comes to designing buildings and elevators.