And the unoriginal rooms will be MUSHROOMS! Oh! It was originally a tool shed shack thing, before the 60s... I think that's the kitchen now... then another room was added, possibly two - they didn't keep super terrific records for a period there, and crawling under the house is a weird maze of kind of seperate and kind of connected various foundations. On the upside, this crazy labyrinth of additional foundations added over time ive the house a super strong base, aside from the newest addition, which has enough room under it for an actual cellar, but could actually use some additional support [which the inspector showed me when I bought the place - it's good enough to be legal, but could stand improvement]. It's survived a bunch of pretty decent earthquakes since that last addition was completed in 1968, so that's also reassuring.