A partner and I own a warehouse in a small market that we're interested in converting to self storage, but it's in a "mixed commercial/residential" zoning part of town, and the only zoning classifications that are permitted to build self storage per their code are the purely commercial zones.

Don't assume you will get a 5 bedroom septic permit.

The idea to invest in real estate came to me a few months after graduating from college about 2 years ago.

So I should check with my county to see about getting a permitted apartment on the property, abide by those regulations, then FHA would recognize the property as a duplex/multiple family or whatever was approved by the county?

I used this method in college when subletting rooms to roommates.

.-2.5 months organizing and waiting for the city to approve drawings and release a permit: I learned the Durham city rules and what they were all looking for in this type of full renovation project and how important it is to have a full set of engineering prints made up asap after buying a property-2.8 months of waiting on contractors to pass inspection: it amazed me how many contractors don't bother to show up to meet the inspections guys when they come out, so there was a lot of this is what it says on paper, but the real problems were not getting fixed, this resulted in a lot of failed attempts to be inspected.

Does anyone have a checklist they can share on number of reports/permits I would need to get at different stages of construction?

Depending on whether it was done legally with permits depends on whether or not a lender could count the income from it towards your income (to help you qualify). 2) Trulia, Zillow, Realtor.com, and many of the other listings sites are pretty accurate.

https://www.biggerpockets.com/forums/52/topics/491641-nearing-1-000-college-student-tenants-heres-what-ive-learned

Are there any multifamily developers in Portland, OR who can give me a broad idea of what range new construction is costing per square foot (not including land/permitting/etc.) these days?