Why do most businesses have doors that open to the outside, while residences and apartments have doors opening to the inside?
In: 1
At least in the USA this is firecode. There was a tragedy in my home city that caused this to be firecode for the whole country.
Once upon a time about 45 years ago a new hotel+convention center was built. It was called the Hyatt – Regency. They hosted a big opening party. And then it all went bad. The skywalk (a bridge over the lobby) collapsed. It fell, and crushed two lower skywalks before all three structures fell onto the partygoers below. It killed at least 42 people.
Somewhere in the chaos a fire started. People panicked and tried to leave. But the doors opened inwards. The crowd was packed so tightly against the doors that there wasn’t enough room to open them. And in the chaos there was no hope of organizing the crowd. The fire killed them. Ultimately 114 people died, with another 209 hospitalized.
At least 62 of those deaths could have been avoided if the doors opened out instead of in.
The initial cause of the collapse was a combination of the contractor making changes for ease/cost, and the negligence of the engineers who reviewed the plans and approved them with the design flaw.
The skywalks were all suspension bridges. Held up by a pole that dropped from the ceiling. The initial design had a new pole dropping from each bridge. Which made the design more complicated, and more expensive, but safer.
The contractor asked to make all the bridges suspend from the same single rod. And the engineers approved it without doing any math. If they had looked into it, they would have realized it meant the weight of all three bridges were now suspended on one plate, instead of one plate for each bridge as originally designed. The plate holding the top bridge was designed to hold twice the weight of the bridge, but not three times the weight. So when the crowded party happened and dozens of people were standing on the skywalks the plate failed. And the first bridge fell. The impact of the first one broke the second and then the third and all three bridges fell onto the party below.
Ninja edit: **So that’s why buildings in gathering spaces have doors that open outwards.** Homes and apartments (and banks and other secure facilities) have doors that open inwards because it’s better security.
Latest Answers