As I think you'll hear a lot of people say, the obstacle is getting started.

On types of ADUs, theres detached, attached, and junior adu.

Hi,A friend is seriously considering building a detached 600 square foot ADU in their backyard in Southern California (specifically the Westlake/Moorpark area in Ventura county).

Be detached (as much as possible) and realize that their life is far worse than yours.

I am a licensed Architect and do a lot of work in the City of Chicago as well as surrounding suburbs.If your lot is RS3, that means that it is in fact "Single Family Zoning" according to the Chicago Zoning Ordinance"17-2-0102 RS, Residential Single-Unit (Detached House) Districts.

You'll be good, and I see more options than obstacles here.    

I learned a lot about the obstacles in getting PPE to the right destinations.

A SFR with a detached garage big enough to convert, and alley access for an ADU in the back with separate entrance. 

I would also start detaching from her games (not doing the unreasonable maintenance she wants).It sounds like she's maybe feeling a lot of hostility and looking for a fight.

How do you split the water bill among 2 tenants in a SFR property (main house and detached unit)?