Already tried: all sorts of combinations of "baba-nyonya" "peranakan" "straits chinese" "house" "terrace house" "floor plans" "architecture" and various place names. And a trip to my university's library.
I'm also curious about the layouts of historical houses found in southern China. There's a lot about courtyard houses and tulou houses out there, but not much about other styles. If you know of good resources for those, then that would be appreciated, too.