My home town has a treasure trove of Art Nouveau buildings in it's historic city center. It's a very desirable area to live in, so most of those units have been renovated over time. Sadly those renovations almost never respect the original and follow whatever trend of the moment.

One thing i'd like to do is to acquire some of the remaining rare gems that remain (mostly) untouched and restore them to their original glory. I ever wonder if there is room for a business model here, like home flipping but with a side of restoration and preservation.