SB 10 is voluntary; but for the cities that do choose to use it (or selectively use it), now neighbors can’t sue to stop anything 10 units or less from going up based on environmental concerns. It’s big for that reason.

SB 9 is paradigm shifting: every lot in California that’s single family zoned can a) be split into two lots AND/OR b) each resulting lot can now have up to 2 units AND c) if the lot is compliant with all other criteria, each lot is still able to have an ADU built in addition to the extra unit, per statewide ADU law passed two years ago

So you can potentially turn a single lot into 6 units. Or 3 without splitting the lot.

All of this is by-right, too. Design approval and local councils can’t stop it, and I believe they must be approved within 90 days, too.

This isn't quite right, unfortunately: you can only have 4 units per parcel, not 6. That's because SB9 includes ADUs in the definition of "unit," so it cannot be used to create a duplex on a lot that already has ADUs.

Thus, SB9 increases the limit from 3 units to 4 units, not 6.

You’re right, I must have read an earlier version of the bill

https://leginfo.legislature.ca.gov/faces/billTextClient.xhtm...

“Notwithstanding Section 65852.2 or 65852.22, a local agency shall not be required to permit an accessory dwelling unit or a junior accessory dwelling unit on parcels that use both the authority contained within this section and the authority contained in Section 66411.7”

However, it does not appear that the law prevents an ADU from being built without any additional rezoning, just that local cities may choose to approve/disallow it as they see fit

AB68 applies to multi-family lots as well, and you're allowed up to 2 of them, detached from the main multi-family building:

https://leginfo.legislature.ca.gov/faces/billNavClient.xhtml... (section 4).

Do the lot split first, then the duplex construction, then construct 2 ADUs. 8 units where a SFH was before.

> It includes provisions to prevent the displacement of existing renters and protect historic districts

This is specifically in reference to the owner-occupancy provision. If you choose to split your lot into two parcels, the owner must attest that they intend to reside at the property for at least 3 years. This concession was made to satisfy a demand from the California Association of Realtors and get the bill passed.

Note that this is different from the duplex provision: each parcel can have a duplex, regardless of whether you split the lot or not. The duplex provision does not have any owner-occupancy requirement.

> So it's voluntary?

SB10 creates a voluntary process for 10-unit apartment buildings near transit. SB9 is involuntary, and allows duplexes and lot splits in single family zones.

They're starting to get more voluntary because of SB35. They can voluntarily decide where to build now, or helplessly watch a judge rubber-stamp whatever the developer wants to build once the city is designated as behind their RHNA requirements.

SB35 ends the days where "local control" included an option to not build anything.