Thanks for the feedback on this.
My understanding is the same as Josh’s. If a room has an egress window it can count as finished, as long as the space is livable. @Sarah, hearing about the walkout as another option is helpful too.
And that’s a good idea on calling an appraiser to ask about the 1 to 1 value comparison of finished in basement vs above ground levels. If it’s similar, I think adding an egress window or two could make sense assuming the basement is already livable and doesn’t need a lot more done. I heard a quote of 6k to install one egress window recently, which sounded pricey to me, but seems well worth it if it creates enough additional sq ft of finished space. For the property I'm looking at, there would need to be an egress added to a bedroom and a second added to the family room for a total of 600 sq ft of finished space.
Assuming it is 1 to 1, it seems like a good move based on this scenario: say all you need to do is install 2 egress windows for 10k total, and put another 10k in other finishes, and Portage houses are currently selling for an average of $163/sq ft - that’s equivalent to adding 163 x 600 sq ft = $97,800 - $20,000 = $77,800 in value added. Which leads me to think this is too good to be true, and that finished sq ft in basement is not comparable to finished space above ground.
But I'll check with an appraiser and once I get more info on this, I’ll share out on what I find here.