People in Europe do not worry about reusing old stuff. The continent is packed full of old stuff. Every time they dig for a parking lot a tomb or an ancient villa or red figure vase turns up. If people didn’t upcycle, nothing would ever get done.
Here’s a superb example from the old quarter of Barcelona. This used to be the temple of Augustus, Roman emperor promoted to deity. Quite a standard space, columns and so on. But time, and the city, marched on. Pieces of the old building were taken away to build other things, and the former space was encroached upon by new structures. Until finally you have this.
The apartment building next door not only used the columns and pillars in the wall, as that church in Rome did. They’ve completely surrounded the entire former temple, digesting it like a python swallowing a guinea pig. This interior courtyard allows daylight into the inner windows, which peek out right beside the ancient columns. You can get in to see the ruins, and the residents can look down at you.