Excellent generator. I had been trying to program something similar myself and hadn't got anywhere near as far as this. I was still stuck at a single story! From playing around with this, I can see that you have had some of the same issues I had - namely illogical room layouts - particularly in larger structures, sometimes with redundant corridors, sometimes with bedrooms that lead to other bedrooms etc. Trying to wrap my head around the logic there was a nightmare, so I take my hat off to what you have achieved!
Some future features you might want to consider.
1) Additional external doors. Most houses have a front door and a back door - sometimes more than one.
2) User defined room labels
3) Grid size. Is it supposed to be a 5 foot grid? (i.e. usual D&D battlemap size!) Some of the rooms come across a bit small based on that size, but if it one considers it to be a 10 foot grid then that makes most of the corridors and rooms that should be small (I'm looking at you bathrooms), would be rather large.
4) Improvements to the "furniture" in the rooms from the bare outlines of rectangles and odd shapes. There are quite a few libraries of top-down graphics of furniture that could be dropped in - with suitable ones selected for genre/room type.
5) Export Options. Might be worth considering collaborating with a Foundry module developer to enable an export to Foundry. Especially the multi-floor views of a building. Also, maybe an export to a graphic format that will effectively save the building as a set of graphic files labelled appropriately, one for each floor/elevation view.
I can probably come up with further suggestions - but that might be more than enough to start with! Again, major Kudos for your efforts!
Matthew