Why do buildings (sometimes) not include seemingly obvious safety measures from initial design?


I’m often struck by buildings with safety measures that have clearly been added on later, e.g., railings, fences, etc. Like this view from a proposed observation deck on the Chrysler building: https://cdn.vox-cdn.com/uploads/chorus_asset/file/19989364/Screen_Shot_2020_05_20_at_11.07.25_AM.png (from https://ny.curbed.com/2020/5/20/21264740/chrysler-building-new-observation-deck)

Even the original railing itself looks like it was an afterthought. Why would the original designer think that a knee-height wall was a sufficient safety measure for a terrace?

In: 15

Why should it have safety measures for a purpose it wasn’t designed for?

It would add both cost and make maintenance more difficult.

Also who said it didn’t meet safety requirements in 1928?

1. A lot of things are only obvious in hindsight.
2. A building’s, and the various spaces within and on the building, features and function change over time. For example, the observation deck may have only been originally intended for maintenance work.
3. People will always find a way to use things in a way never fathomed by the designers.

In a case like the one you linked, the original pipe railing was never meant for tourists. It was meant for workers that are up there for a specific job. Fixing an HVAC system, changing light bulbs or other maintenance. So, theoretically, no one is up there screwing around. They’re up there for a specific job, they are trained on the risks, they may even be tied off so they fall protection.

In the ‘proposed’ picture, it’s meant for anyone that walks in off the street to go up there with no danger of falling because the only way to get near the edge is to climb a vertical glass wall.

The only people walking in off the street and making it off the edge of the building are doing it on purpose and tend to be difficult to stop regardless of safety measures in place (think: BASE Jumpers).

Also, keep in mind, the Chrysler building was built 90 years ago. Even if those pipe railings were an after thought, they didn’t think about safety 90 or 70 or even 30 years ago like we do today. They were meant more to let you know your close to the edge rather than to prevent you from falling.

Having said that, I to am also bothered by knee high safety measures like this. You tend to see it when a large, flat roof building is getting work done and the put a string with flags on it around the edge. I understand the reasoning, but if it was waist high, at least you wouldn’t trip over it if you walked backwards towards it (and, protip: don’t walk backwards on a roof).

I’m not an expert, but based on conversations I’ve had with my architect uncle, it comes dowm to cost vs benefit.

Contracts (generally) go to the lowest bidder and a lot of the time, designers and builders deal with constant delays and set backs so they make up the overspending by understanding in some areas. You also (according to my uncle) need to consider how many people are likely to use that part of the building. An elevator? 2 fail safe systems and the laws of friction mean that it (ideally) will never fall fast enough to kill someone or slam their body against it’s roof. And even if it does, there’s an emergency button and phone number. That’s because pretty much everyone uses the elevator.

But the very top of the building? Just tell the building owners to lock it. Realistically, only like a dozen people a month will go there. So pay for the extra expertise and machinery neccessary to haul heavy large rails that high when you can just put up smaller cheaper ones that meet the legal “standards.”

I would argue that both images have their drawbacks and are equally an “after thought”. The railing doesn’t protect / secure the average visitor while the glass doesn’t provide fall protection / awareness to workers outside its perimeter.