Additions and Lot Coverage in California - Potential Loophole?

[Izzie Y.]

I am working on renovating a multifamily building on the Westside of Los Angeles county and trying to figure out how to navigate a situation. Here are my objectives:

OBJECTIVE #1: Do a 150 sq ft addition to one of the existing units
OBJECTIVE #2: Convert two covered garages into a single ADU

Problem: the city zoning allows for a maximum lot coverage of 45%. The current building is above that at 46% (and is grandfathered in from old zoning rules). Therefore with the current lot coverage amount, there is no way to do an addition as we are already above the limit. However, the new ADU laws in California that went into effect Jan 1 2020 may provide a loophole.

As I understand the laws, they say that the city cannot use lot coverage to prevent you from building an ADU under certain circumstances, therefore I wonder if I could do the following:

STEP #1: Convert two garages into uncovered carports, causing them to be removed from the lot coverage and bringing our lot coverage well below 45%. Do the 150 sq ft addition which still leaves us below the 45% limit.

STEP #2: After the above project is complete and passes final inspection, convert the two carports into an ADU. Even though making them into ADU would bring our lot coverage well above 45% , the city would not be able to prevent us from doing so due to the state law

This seems silly and highly inefficient, however it may be the only solution. I am wondering if this logic is sound, and interested if anyone has done something similar. I do not know if it will be cost effective, but my first step is to see if it is possible and then I will investigate costs. My biggest fear is finishing step #1, and then failing on step #2 due to some random rule I am not aware of, and having sacrificed two garages for an addition, with no possibility for an ADU.

Appreciate any insights or perspectives.