Idea about Building Tiers

So I just saw the Twitch stream where Steffani was talking about having buildings in different kind of tiers as your town grows.

Wouldn’t it be cool to not only be able to have new buildings, but also to be able to UPGRADE your old ones?

In other games, e.g. Age of Empires or Anno it was a cool and rewarding visual effect to see your buildings evolve from stoneage tents to big townhouses.
When I build my Stonehearth towns I always face the “problem” that I got the outpost style buildings in the center of the settlement.
Instead I would prefer to have a town center where my Cottage for Two can evolve to the mayor’s mansion.
Also my fortifications look a bit outdated after a while. Or the tiny church I built at the beginning could become a cathedral over time…

The only limitation I can imagine is that the structures can only upgrade their height and details/interior, but not their width as there might not be enough space around them.

So what I am suggesting is: If we get different tiers of new default Buildings, why not make the old ones (optionally) upgradeable to fit the new style of our tier X city?
I am not sure if an option to make custom buildings also upgradable to other custom buildings could also be possible…

Did anyone count how often I wrote “upgrade”??
Upgrade everything!!