This generator works like this: first it creates floor plans made of rooms. Then it builds a list of room types this house needs: kitchen, bedrooms, armoury etc. It's always a reasonable list (e.g. there are as many bedrooms as there are floors). Then the generator tries to assign the room types from that list to the rooms of the house and here it often fails, because each room type has its requirements (e.g. a bedroom can't be placed in the basement).
Hmmm... I find it odd that it doesn't assign the bedrooms then... maybe the problem was the rooms weren't rectangular... in which case it needs to create less "wiggly" hallway rooms and more rectangular rooms (which would seem to make more sense anyway as human houses (at least) tend to be dominated by rectangular rooms... even hallways often are! :)
Edit: Just want to add that I agree with your strategy, I can't think of a better way to organise it without changing the result entirely and creating a cave / underground habitat / hobbithole generator where I would expect round rooms and twisty passages and so I'd probably decide the rooms, place them in proximity and then add linking passageways... so kinda the reverse of this house generator! :D
Okay, I've been fiddling with the Javascript and I can now get bedrooms (unreliably), I just wasn't getting them and then I changed the counter that was adding them (_g) from 1 to 0 so there was an extra one added and now I regularly get one... but only one!
I also tried to add tiny and huge buildings by adding them (almost) everywhere a search found the word "large" (it found a function "*enlarge" which was clearly not relevant) but it hangs for some reason, I can't find anywhere where the number of possibilities is only allowed to be three and I made sure to fix the bits in the grammar.json so the naming was not messed up but no joy... other minor tweeks seem to have worked in the naming and it seems like that would get entirely run through every time the program runs so it seems sound, it is just the runs that include a "tiny" or "huge" tag or randomly include one (one in nine times for each - I changed the frequency to 1,2,3,2,1 to reduce the number of extreme buildings).
Any thoughts?