My local government thinks when it is over 75% done, it's considered
finished. Lot of folks leave it there which won't increase tax.
Like leaving the ceiling unfinished, bathroom not finished, etc.
You can still use the space.
One measure is construction valuation, e.g. $50/sq.ft. is finished.
Other jurisdictions may just use the definition "habitable space" and
use common-sense judgement. Is it storage, or a rec room?
Anyway, looks like you need a local code consult.
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