[Swizec]

> but in another century, there will be no modern buildings still standing

You sure? Many modern buildings are already 100 years old and in active use.

Empire State Building, for example, was built in 1930. Chrysler Building is from 1928. White House is from 1800.

I think we’ll be fine. Percentage wise we might end up keeping more modern buildings than we did of the very old ones.

My mom’s socialist style block of flats (in Slovenia) is from 1962 – 63 years old – and people keep living here and maintaining the structure just fine. Can easily imagine it sticking around for a long while yet.

[ben_w]

> White House is from 1800.

The facade perhaps, but not the inside which dates to c. 1950: https://en.wikipedia.org/wiki/White_House_Reconstruction

[bluGill]

Any building that is in active use needs to get major remodels every 30-50 years, and less major remodels every 5-10. The whitehouse has had significant changes since 1950, though not to the level of the 1950 changes.

[SoftTalker]

My parent's stick built tract house is 60 years old and basically fine. Buildings last pretty much indefinitely as long as they are maintained.

[fransje26]

> Buildings last pretty much indefinitely as long as they are maintained.

Not necessarily, no. Reinforced concrete infrastructure has an average lifespan of 50 to 100 years.