For me it depends on family sizes, but sometimes i also like to build huge manors for 8 sims only.
Thanks to Twallan mods i have fun building houses for 16/24/32 families: from manors to big, modern, multilevels houses.
My first building law is "No swimming pool" because sims and specially plumbots tend to pass all the time on pools and it's a really annoying and stupid thing.
But i like to build small houses too, maybe not claustrophobic. Last one was Sherlock Holmes house as seen in "Testament of Sherlock Holmes" adventure game (great game, great atmosphere) while now i'm working on a huge mansion for 16 sims in Midnight hollow, with huge rooms with lots of store content.
Another thing i do is to place a sauna in my houses for washing needs, because i like to see sims chatting together in sauna instead of taking a shower o a bath alone. In huge houses with 16/24/32 sims, i always build a big bathing room with several sauna: it's very nice to see dozens of sims chatting, bathing and interact all togheter ^^