[Jasoncw]

That's not really true.

Prewar buildings, especially buildings built before the 1920s aren't particularly well constructed. The way they put together the facades wasn't super great. Cornices fall off, and other parts of the facade fall off. Or, if they're not falling off, if you look closely at an old building there are a lot of cracks on the facade, and places where the stone is broken from water getting in and freezing.

And remember, in the 1950s, a lot of buildings were demolished because they were having maintenance or structural problems. You can count the decades back to when the demolished buildings were built... Can you imagine today us demolishing a post modern building because the facade was collapsing onto the street or the structure was failing? Or demolishing a building from the 50s for the same reason?

Or continuing with the subject of functionality, prewar buildings have horrible floor plans. The floor plans tend to be bad for offices because the floors are small and convoluted, and they're bad for residential because so many of the windows either face alleyways, or are party walls between the buildings.

"But so much craft went into that ornament!" Most ornament was hand crafted in the same way that nike shoes are hand crafted. Manual laborers in sweatshops made the ornament, and the companies made certain ornaments and had ornament catalogs so the architects could choose one of their standard ornament products. If the ornament is stone then they were mass produced by hand and if they were terra cotta they were mass produced from molds (terra cotta was first used as a cheaper faux stone). Sometimes genuinely crafted ornament was made but most ornament on most buildings was not.


Anyway, my point is not that those buildings do not have value. My point is that we preserve them in spite of all of their functional failings. Architects bend over backwards getting those square blocks to fit into those circle holes and spend a lot of money in the process.


Now, what makes a modern building "obsolete"? A modern building is obsolete when it needs new windows.

When is a prewar building "obsolete"? A prewar building is obsolete when taking the building apart piece by piece and reengineering the structure and the facade and rebuilding the entire building is not possible.