My house was originally 1500 sqft. They added a 300 sqft back room/den. I have a half finished basement which doesn’t count for square footage. And I added a dormer upstairs last winter that was only about 300 sqft on paper but got rid of vaulted ceilings so it was equivalent to nearly double that. Gotta remember this is in the northeast and built in 1957. Things were different then and an open floor plan didn’t exist.
I’d say my house measures out to about 2000-2200 sqft now without counting the basement.
PS. Doing demo “neat” sucks. Takes forever to be nice about it. I like wailing away with the hammer and unfortunately couldn’t do it that way with this job. Twin 13 month olds and a 3.5 year old slows down progress big time.