How do you see this in practice? Would you like each building to have its number written on the top?
Putting a circle with a number in it over each building will mar the aesthetic, but allows for the option to create two images of the village - one unmarked to present to players and another with the numbers for reference/lookup.
Maybe an option to automatically add numbers to each house, and more fine-tuning one to just add option to context menu? What do you think?
I'll consider something like this👍