That creates a remarkable set of perverse incentives akin to what's seen in Australia, where restoring old houses properly is so expensive that they tend to be left to rot and/or mysteriously catch fire instead. Is the issue widely known?
A similar thing happens in the USA with houses declared "historic". It's well known among realtors and other groups, but not extensively known. Some states/localities have funds to somewhat help with maintenance, but they get depleted very fast, and you often have requirements like "cannot replace the switches with modern ones, must use push button switches" and similar things.
At $15 for a switch vs $1, those things start to add up.
In some poorer places it gets so bad the fire department will basically "wink wink" tell you how to burn your house down.
Other areas have a much nicer version which is "remain visually similar" - basically you can't change how the house looks from the street but you can do whatever you want/need inside.
This has been ironically known to happen on government property as well, where you might expect more desire to preserve historic property. Instead of fixing them, they may just be left to deteriorate until they can be razed and something more modern built on the site.
