LA provides this information on how to administer the interest:LA rent control info Only properties covered under the Rent Stabilization Ordinance are required to pay interest on security deposits, as your link points out, but not all properties are covered under RSO, detached SFR's are not covered for example ... 

This may take some creativity, and you may also need to tap that equity to pay the equity difference on the assumption.Get started and lean on the community when you hit obstacles.

@Chris Seveney is right.My personal experience in San Jose, California was that we spent about $300K to build a detached ADU over a garage and that the appraiser only added $150K value to the appraisalal. 

It's hard enough to control the variables when you have a single, detached unit.

Its a brick rancher with detached garage.

My biggest obstacle has been the analysis part of this business, give me a regular multifamily property and I’m good to go, but this is such a different concept and it has me a little outside of my comfort not having that 12 mo lease and a sizable debt service and utilities to pay! 

Two units above the store front with detached unit above the garage.  

We do have a house almost in Cumming with a detached apartment and RV garage that cash flows well, but have owned it for 10 years.

There's a company building 3D Printed homes in our area, the first in CA I think, and that's one of the obstacles they had to overcome, as the walls are concrete. 

Yup, a lot of DSCR Lenders have moved towards allowing the cash-out proceeds to count towards the liquid asset reserves, so thats not even an obstacle for DSCRE!