9/11 changed architecture and urban design forever

In the UK we had the IRA bombings[0] up until the mid-1990s which changed architecture and urban design. If you worked in the financial district in London, for example, you would have had to pass through the &quot;ring of steel&quot;[1] to get to work, none of the buildings had large car parks underneath (that&#x27;s one of the things that surprised me on my first visit to New York - some of the tall buildings had several floors of car parking underneath), the few vehicles which were allowed into the small car parks were always inspected carefully for bombs, building windows were shatterproof and offices typically had plans showing the red, amber and green zones for blast debris so seating could be arranged accordingly, all post was X-rayed coming into buildings (a colleague once inadvertently triggered an alert by having a plastic light gun for his Playstation delivered to his work address), etc. All before 2001.<p>[0] <a href="https:&#x2F;&#x2F;en.wikipedia.org&#x2F;wiki&#x2F;Provisional_Irish_Republican_Army_campaign" rel="nofollow">https:&#x2F;&#x2F;en.wikipedia.org&#x2F;wiki&#x2F;Provisional_Irish_Republican_A...</a><p>[1] <a href="https:&#x2F;&#x2F;en.wikipedia.org&#x2F;wiki&#x2F;Traffic_and_Environmental_Zone" rel="nofollow">https:&#x2F;&#x2F;en.wikipedia.org&#x2F;wiki&#x2F;Traffic_and_Environmental_Zone</a>

Remember when buildings complexes had multiple entrances ? It is increasingly rare nowadays. Using private but publicly accessible ground as thoroughfare is on the way out too. Fences go up everywhere - though 9&#x2F;11 is only one part of that security paranoia... My apartment building in La Defense is the only one left on our street with a single layer of access control - two is most common and three is the standard nowadays (and when I was a child, in the early 80&#x27;s, there was none and it was normal). I don&#x27;t want my city to feel like a compartmented facility.

I&#x27;d say the Oklahoma City bombing had a far greater impact in civil engineering and architecture than 9&#x2F;11. The Oklahoma City bombing jump-started an awful lot of research into new topics such as progressive collapse, quantification and classification of dynamic loads from explosives, structural modeling techniques, and even design of passive defenses to mitigate the impact of these structural actions. Not so much 9&#x2F;11 in general and the twin towers attack in particular. I invite anyone to run a few queries on Google scholar on the topic to get an idea of how the Oklahoma City bombing pops up in quite a few papers evem up to this day.

9&#x2F;11 had nothing to do with the fences around the Eiffel tower. Those fences were put up in 2016 because of increasing terror attacks in France.

Among the other things it changed forever: travel, immigration, privacy, government excesses, etc.

If anything has changed urban design, I&#x27;d say that it&#x27;s the huge growth and normalization of homeless populations. You&#x27;ll see a disinterest in building urban parks, so-called &#x27;hostile&#x27; architecture, less interest in things like downtown libraries, etc. etc.

So many places with obtrusive security presence, security checkpoints, etc; still have a side door propped open around back somewhere that lets you wander through the &quot;controlled&quot; area freely.<p>The &quot;defensive design&quot; things like bollards and big planters that block walkways are like rung 1 (or 0.2, perhaps) on the &quot;defensive earthworks&quot; ladder. Its a well studied field and there&#x27;s counter-actions available for most of that kind of thing. An attack may become more expensive to prepare and require more resources in flight but the bollards and defenses can be hit first and removed.<p>Judging by the <i>results</i> off all the upgraded security measures since 9&#x2F;11; we can see what is actually feared.

I think it&#x27;s funny how some of these bureaus take themselves too seriously. ISIL probably doesn&#x27;t care much about the new ATF headquarters, it&#x27;s not a cultural landmark.

I think that really started after the Timothy McVeigh bombing of the Alfred P. Murrah Federal Building in Oklahoma City in 1995.