DecBytes on Nostr: I can't say for sure. In order to preserve the historical look and feel of Portugal ...

I can't say for sure.
In order to preserve the historical look and feel of Portugal they have laws to preserve building & calçada (pavements) etc. I think this is the primary reason for existing buildings.

Where I live they are building new developments and they also chose to use calçada on the sidewalks. Probably the developer chose to do it to increase the value of the houses.

You also have a limit to how much of your land may be covered in building. I think calçada is not counted in this calculation, while concrete sidewalks are counted.