This article explains it a little bit:https://authorityappraisals.com/2019/01/how-to-measure-a-home-gross-living-area/If they do a comparison to other triplex with a unit in the basement, the appraisal should still hold up because the above ground square feet would have higher value. 

For example, the bottom 10 metros for GMP/capita (measurement of a metro area's output based on national prices for the goods and services) of the largest 53 metro areas in the US, include a few Rustbelt cities, but surprisingly the list over indexes in superstar growth metros in the Sunbelt.  

Regarding COVID-19, we believe COVID-19 will be an ongoing health and safety risk that all business professionals will have to manage with informed measures.

The definition of "unfinished" can be disputed as well, and measurements can just be off.Another factor is that lots of money put into things like custom landscaping, exotic fixtures, outdoor living spaces and even flooring materials might add zero value to an appraisal even if such items would entice a knowledgeable buyer to pay top dollar. 

Why don't you measure it to get a approximate idea?

Measure the openings to make sure.

Tenants are comfortable with the measure of control they have, and it's a fantastic help for me.

I measure cash purchases with ROE.

Hi @Aaron Ross, how are you measuring your return?

I believe it was used previously for the swimming pool heater, as it was situated right next to the heater in my backyard.My concern was if they move or cut it to pieces and if the gas spilled, I will have some sort of EPA hazard waste disposal issue - one of my neighbors said the city will force you to dig 3-4 feet either side of the spillage to make sure no additional soil is contaminated.I took a picture of it, measured it, and posted it on CL, said I wanted it removed and disposed of, and the gas inside feel free to take it but it needs to be completely siphoned out before you can take the drum apart.