Not sure I agree with either the estimator or the comment that if it's only accessible from the outside it won't be counted. Homes with accessory apartments (legal) in the basement are listed with that space included in their total square footage. Sounds, to me, like the "estimator" just doesn't wish to change his/her report?
If the basement is accessible from within the home and it's heated it can most likely be included in square footage. If the only way to get into the basement is from outside it won't be included in the total square footage of the home.
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