@43d7c4ea 
The problem with a) is that when they were built in the 1970s never-ending austerity due to ideological arguments was not yet universally accepted in the UK, so people could plan with reasonable maintenance.

ad b) which bigger public building does not have some serious issue. Don't get me started on the beautiful university buildings built in the 70s/80s in Vienna, not working air vents are the tiniest of the issues, some are literally ruins by now. 

 @d598c4a5 

Yes, I agree; the key problem is that building with materials that require ongoing attention always also requires faith in the ability for maintenance to continue.... but also building quality has always been an issue.

Our older building stock offers an example of survivors' bias... we don't now see all the older building that failed for one reason or another & were demolished or collapsed in the past