> and this usage was given a "shelf life"

While it might technically be true, that surely does not absolve the engineers who did this crap.

There is a general social expectation that new buildings should be structurally sound for a duration on the order of a century. So, if you deliver something that has a mean time before catastrophic failure around 30 years, you also need to account and set up the institutions that will handle the failure, the same way nuclear companies are required to set aside money for their decommissioning. You need to have periodic inspections for signs of early failure etc. and this whole circus needs to be disclosed and priced into your tender.

In reality, this entire fiasco was a dirty and cheapest way to satisfy the contract, ye old "good enough for government work" as evidenced by the fact no substantial number of private buildings of the same period are having this problem.

The maintenance provision was snuck into - or bribed into - some mountain of legalese, but the fuckers knew exactly that they were putting children in harm's way.