When I bought this 40-yr old 2-storey house (here in Canada) a couple of years ago, was told the floor area is 1800 sq ft. Lately I measured from inside wall-to-wall for getting estimate for attic insulation, it's smaller than that (less than 1750). I think this is the "interior floor area" used for "house for sale". Is there a standard way for the measurement?
Thanks,
John