The lifespan is kind of a complex issue. I think generally they can last for a very long time if maintained. But that often the maintenance costs can exceed the

The lifespan is kind of a complex issue. I think generally they can last for a very long time if maintained. But that often the maintenance costs can exceed the point that it’s worth doing. Australia has a situation where a lot of public housing buildings are 60+ years old and while still structurally sound, they require refurbishment to keep running well. But the problem is living and buildings standards have progressed so much since construction that even if they were restored to like new conditions, they would still be sub standard. So it makes more sense to demolish and rebuild.