Close to colleges, hospitals, shopping, great schools, etc.Lately, we've been throwing around the idea of creating/building an accessory unit/small cottage on our land and renting it out like a regular rental.

Welcome to BP @Claire SeversonAs you know multifamily housing is incredibly rare in the DC metro....and Northern Virginia is the area that has the least amount of an already small amount metro wide.It is highly unlikely that you would be able to find a buildable lot that has zoning that allows for multifamily use.A few local jurisdictions allow you to put in basement apartments...but I think Fairfax county is pretty restrictive on allowing accessory dwelling units.

I roughed framed the new tub location and installed a rough opening for a new built-in style medicine cabinet along with additional blocking for towel bars and future accessories. 

This type of project here is referred to as a JADU (Junior Accessory Dwelling Unit), since it is attached to the primary residence it is classified as a JADU as opposed to a traditional ADU (Accessory Dwelling Unit). 

An Accessory Dwelling Unit? 

Lots of accessories to really make the kitchen pop.

@Chris Seveney  they are quite popular in PDX we call them ADU  accessory dwelling units and usually are above the garage...

I'm looking at owner occupying, so one option I'm looking into is an Accessory Dwelling, and I'm waiting to hear back from zoning on if this would solve my problem. 

In many areas, you will want to get your stationary tiny home built and permitted as an ADU (accessory dwelling unit). 2.

That would make residents accessories to this heinous crime!