[zardo]

I think that's only used for structures immersed in seawater.

It's not that we can't design buildings to last longer, it's that you don't want to design a building to last two centuries when you know it's probably going to be torn down in 50 years no matter what shape it's in.

[meltedcapacitor]

Stainless steel rebar is also used for (not only seaside) bridges etc, but at 10x the cost it's not going to be in ordinary buildings.

If a building is made harder to demolish than its neighbours it's got a better chance to survive. I plan plutonium-core concrete walls for my mausoleum to prevent future generations from interfering with it.