Example that comes to mind: my alma mater tore down a building that contained english/math classrooms and lecture halls, and replaced it the year I graduated. The basic requirements of an english/math classroom or a large lecture hall have not fundamentally changed in the last 100 years, they may have added projector screens but it's still fundamentally a room that people sit in and receive instruction, and there was no real need to replace it besides "we could".

The university did put forward that it would save them $300k per year in energy costs, which means that at the cost of $69 million it'll only take them 210 years to make their money back.

https://www.mlive.com/news/kalamazoo/index.ssf/2010/05/weste...

They are currently planning to tear down 12 student dorms and rebuild them at a cost of $55-75k per bed.

https://www.mlive.com/news/kalamazoo/index.ssf/2017/09/weste...

That's the kind of thing that drives up costs.