Slot machines get some extra income lol

If so building a DADU / Backyard cottage is a no brainer, as the main hurdle for these builds is the difficulty in financing them.

I use the storage room at my apartment building installed a very nice mail slot and gave the door a number.

@Alexander Reid what does your financing look like for the DADU? 

I've seen some new construction townhomes with ADU's or DADU's as well - a lot of areas do not allow these, but Seattle, Bellevue, and Tacoma do allow them in one form or another.

@Brian Hughes my understanding is that the rules for adding a unit to small multifamily are completely different from SF zoning ADU and DADU permitting.

Right now I have 2 open slots, possibly 3keywords: delco, delaware county, philly, philadelphia, Montgomery county

These are the two ADU / DADU markets where investors should be focused - not just because of friendly ADU/DADU regulations, but also because of the strength of the rental market in those cities.There are some absolutely killer investing strategies you can build around this (SFH + DADU + Opportunity Zone Fund for instance, which would make all of your cap gains tax free), and DADU costs in particular, although high, are coming down. 

I was also able to add parking rent for 3 spots as all 3 tenants requested extra assigned parking slots.

We are looking to turn our current primary house into a rental after we build a DADU.