And guess what, he was given a cease and desist order, shutting down his business until he had a new location where he could legal run the business. 

PG County isn't the hottest market in the DC area but the property is located near the future Purple Line so there is appreciation potential.

I found the location and ..... very agreeable to my needs and I look forward to working with you!

Based on the actual location of this property, you may be a little early to the party. 

Ever thought about renting out the apartment (or similar in different locations where it suits better) per room to students or expats/working people? 

You had a ton of former home owners becoming renters, and that pushed up the demand for rentals almoat everywhere.I tend to get strong rent growth in general as I specifically target locations with strong rent growth.I have however had rents go down in my far far outlying properties from DC.

@James Joynes You said  "Place" did you  mean location?

Is this related to the location of your property? 

Location : (OKC investor please comment about area if you are familiar with this)

BDS has a good Change of Use or Occupancy flyer - https://www.portlandoregon.gov/bds/article/125287 - that lists the exact situation I'm curious about: "changing a house or duplex in a non-residential zone to a short-term vacation rental," but I can't find more detail about it anywhere else.The City has no shortage of info about accessory short-term rentals that Airbnb will partner with Portland to enforce permits for next year, but I'm interested in requirements for non-accessory short-term vacation rentals (as articulated in that link) located in non-residential zones.