Any additional permits?

@Erich HatchFirst, I look at permit history.

Perhaps they would make more money if STR was an option, however if that's not permitted in their location, no STR demand exists, or no STR PM is willing to take on their property, they may not have that option.

For non-primary residences, they have to follow all of the following rules to receive a permit: - the property must be a minimum of one (1) acre in size (designed as a precaution to disturbances)- The building standards of the underlying zone district must be met - Adequate parking is provided - Defensible Space requirements are met - Valid water and sanitation must be demonstrated - No more than five (5) bedrooms are in the dwelling As time goes on, they continue to become more strict on the rules listed above here, and are actively regulating it.

That's a spreadsheet that doesn't transfer to a real life leasing scenario because its not permitted within the zoning code.If the property is zoned RM1, then  perhaps you can lease to 8 unrelated individuals by converting the building into multiple units.

I have started soil tests on 12 lots costing me a total of $5340 for the permits.

It sounds like you can not for any purpose since the conversion is not permitted.

What you would presumably do is find land, buy it, ask for a construction permit, hire an architect to make plans and hire a builder (the developer) for the construction.

I agree, I would be very careful doing anything that is not permitted or allowed based on the zoning. 

I know certain areas where I live are limiting those types of permits, etc.