I haven’t played with the new appeal system, but generally speaking I try to have my buildings fit a common general pattern, and then vary a bit building to building – think Theme and Variations. One general theme, then different variations on that theme.
One example where I feel like I did a decent job is here: Maratas, the City in the Stone (WIP)
I suspect those designs would be a bit too congested now in the new builder, that was before space requirements and appeal came in. Not sure what the “minimum space” a hearthling needs is now etc.
edit: from what I can tell, the minimum space a hearthling needs to avoid unhappiness is somewhere between a 12x12 square and a 15x15 square but I’m not sure exactly (and would appreciate a tip from someone who knows, myself).