I've been knocking on doors, there is one that seems like it's abandoned, however despite finding the owners name from tax records I cannot seem to get in contract with them to make an offer (despite trying x, y and z). 

It also has a 1700 square foot finished basement, and a brand new 3 car garage, with 1100 square foot luxury apartment above.  

Hi Jaycee,I currently own 40 doors and I have good equity in them.

Those couple of little small stress cracks  in the wall you took a picture of as well as the hole in the door are easy fixes.   

I used Three Doors in St.

This is true of parking spots, sheds, garages, etc. 

Here's how I’ve successfully found off-market properties:Direct Mail: You can pull lists of absentee owners, tax delinquencies, probate properties, and more, and send them direct mail offering a cash sale.Driving for Dollars: This means driving through neighborhoods looking for distressed properties and either leaving a note on the door or contacting the owner.Cold Calling: Use public records or services like Prop Stream to pull lists, then contact owners directly by phone to see if they’re interested in selling.Networking with Agents: Many real estate agents work with investors and have access to off-market deals (pocket listings).

So for example if I rezone from RS-3 to RM4.5 and add a basement unit (4th unit), maybe I can then add a ADU above the garage, or do another studio in the basement, once the citywide program is opened up?

Things that you can do or have access to that not everyone does.

Investor who bought house next door to me said he is having difficulty finding "good" tenants.