In the event that the inspection requires major configuration changes to this furnace, I wanted to get some ideas and suggestions from fellow landlords.   

For many people in NYC, the Air BnB model offers a significant opportunity within the framework of your primary residence - for example, if you live in a 1 bedroom apartment right now, possibly get a 2 bedroom and configure it for guests to stay while insuring your privacy.

Also, what are the monthly rents and unit configurations?

Here is the information.Duplex #1 sits on a residential land with a 2/1 configuration, both units are occupied by long time tenants.

Weird configurations don't rent or sell well. 

For this asset, we are re-configuring a 4BR1BA unit to an easier to lease and higher rent generating 3BR2BA unit.

but as you point out that doesnt mean this is a legal configuration.

Metrics and spreadsheets don't fix bad tenants, not knowing local ordinances for landlords, not understanding the configuration of neighborhoods.

This could be done by adding on to the home, by re-configuring the interior, or both.I am only aware of the ADU laws allowing for one additional unit to the main home. 

.- Doing a complete inspection of one building usually takes 3 - 5 hours depending on the configuration even if you just spent 1 hour per building which is a kick the tires kind of cursory look would equate to 10+ hours to include the common spaces When you're talking about commercial deals there is a lot more than just I didn't like the color, it doesn't have crown molding, and the roof showed signs of significant wear.