Different size 2D Palette Buildings approach?

Hi, I’m working on a strategy game.
I’ve made a 2D generated world using the tilemap palette system.
Now I’m working on the buildings section. The issue is that I have buildings of different sizes like 1x1, 1x2, 2x1, 2x2, 2x3 based on the palette of the original world generated.

First I thought that I’d make a different tilemap palette for all of them and slice them up based on their sizes, then I thought that maybe I should Just slice them all up in 1x1 sizes and make a group of them with rule tiles for each building. Now I’m thinking that I might not even need to use the tilemap palette system and just make a prefab object of all of them.

What is the usual approach if I may ask?
Thanks

There is no usual approach. Any approach would be tightly adjusted for the game itself.

I would look at some tutorials for games that routinely solve and deal with this issue:

  • tetris clones
  • city builders (as long as they support varying building sizes)