@Kevin Kim What I see and experience is that single-family with ADU is a better investment vs 2 to 4 units as far as ROI and other factors (tenant quality, location, maintenance, etc). Generally, most of the 2 to 4 units on the market in LA have long term tenants that are paying way below market rent and comes with rent control... so you could be looking at relocating the current tenants and also repair and renovate once they move out. Again, there are regulations with rent control so it's easy said than done. Also, many of these will require a bit of work and repair as well.
On the other hand, if you go with the single-family and ADU route, you will be able to get new tenants in that will be at market rent rate in most cases. The cost of building an ADU will depend on what's on property, but generally could be between 75k to 200k. I recommend hiring a contractor and getting permits for the job.
My client was in a similar situation like you and we ended up going with the single family + ADU for the reasons mentioned above.
