The three main valuation approaches are sales comparable (based on recent sales), income approach (based on the NOI and market cap rate) and cost approach (based on cost to replace/rebuild  the property from scratch).GRM, gross rent multiplier, is the number of years the property would take to pay for itself based on the gross potential rent.

Multiplied by 96 units, me and my partner made $1.5M profit on it when we sold it a few years ago.

For valuation, a quick one I've seen is to multiply number of units by 60 and then by 12 months (# units x 60 x 12).

Gross rent multiplier, if I understand it right could give me pretty good value on the building.

It doesn't have to be a lot because you're freeing up an under performing portfolio to do the heavy work of multiplying wealth. 

It's absolutely true that condition and finishes can make dramatic differences in the multiplier.  

This is how much your CF will drop per month.4 - Multiply this number times 12 to give you your CF drop per year.Here comes your answer...5 - Divide the number from Step #2 by the number from Step #4. 

I also recognize I can manually delete the transactions myself when they occur, but my goal is to move more properties over to Stessa, so it will end up multiplying the monthly corrective efforts needed. 

- Why is gross rent multiplier important?

It is a gross rent multiplier not net ad does not account for debt.