A housing-subdivision bill, not another ADU-count rule
AB 2601 makes specified housing and subdivision applications eligible for concurrent processing. It was signed September 30, 2026 as Chapter 955 and is relevant to planning for 2027.
The distinction matters: AB 956 concerns two detached ADUs, while AB 2601 addresses qualifying housing developments and subdivisions. These are different legal routes. Marketing them as four interchangeable “ADU shortcuts” would hide the decisions a homeowner actually needs to make.
Read the chaptered AB 2601 text for the provisions affecting SB 9 two-unit development, urban lot splits and other qualifying small housing subdivisions. The law contains coordinated amendments with other bills; the applicable operative version and application date need to be checked.
What concurrent processing means
Under the specified pathways, a development application can be processed alongside the related subdivision map application rather than treating every review as a strictly sequential step.
That is a process improvement—not automatic approval of both applications. The bill permits agencies to condition issuance of building or grading permits, or certificates of occupancy, on first obtaining approval and recording the required map.
Think of it as reviewing related documents together while still satisfying each legal requirement. Do not confuse an application being accepted for review with permission to start construction.
Three different property goals
| Goal | The question to explore |
| --- | --- |
| Add living space while retaining one parcel | Is an ADU or conversion pathway appropriate? |
| Create qualifying two-unit development or split a single-family lot | Does the property qualify under SB 9 and the relevant subdivision rules? |
| Pursue a qualifying small housing subdivision | Which subdivision pathway, eligibility rules and map requirements apply? |
AB 2601 does not erase the eligibility conditions of the underlying programs. It also does not itself authorize every homeowner to sell an ADU separately.
Why splitting a lot is not just drawing a line
Subdivision planning can involve surveys, access, utilities, easements, title conditions, map preparation and recording. Financing and ownership goals may also affect the choice.
Before pursuing concurrent applications, establish whether you want rental housing on one property, family accommodation, separate ownership or a larger development. Then ask the relevant professionals which legal route supports that objective.
A builder can assess site logistics and construction scope. A surveyor, planning professional, title specialist and attorney may be needed for subdivision and ownership questions.
What LA and Orange County homeowners should gather
- Current property and permit records.
- A site survey or reliable existing plan, with easements identified.
- The proposed unit layout and access concept.
- Existing and proposed utility arrangements.
- A clear description of the intended ownership and use.
- The reviewing agency's current application checklist and instructions for concurrent review.
For Whittier, Anaheim and Santa Ana, work with the city's own reviewing departments rather than assuming the City of Los Angeles process applies. Properties in unincorporated areas require a separate jurisdiction check.
How this fits the four-part series
The practical sequence is to select a legal pathway, test the site, compare designs and then coordinate applications. A fee change does not establish buildability, and concurrent review does not establish subdivision eligibility.
Read our existing SB 9 lot-split guide for background, then verify the rules applicable to a 2027 application. This new article is about AB 2601's process change, not a replacement for that property's eligibility analysis.
Discuss ADU versus lot-split project goals. We can help assess the construction options and identify where specialist advice is needed.
Frequently Asked Questions
Does AB 2601 allow me to sell my ADU separately?
Not by itself. Separate conveyance requires its own lawful pathway and approvals. Concurrent subdivision processing is not an automatic separate-sale right.
Can construction start while the map is being reviewed?
Do not assume so. The bill allows specified approvals and permit issuance to be conditioned on approval and recording of the required map.
Does every property qualify for an SB 9 split?
No. The underlying eligibility conditions still apply. Confirm the parcel and the current operative law with the reviewing agency and qualified professionals.
Read the What's Coming in 2027 series
- Part 1: AB 956 and two detached ADUs
- Part 2: SB 1117 and ADU impact fees
- Part 3: AB 1621 and housing permit reviews
- Part 4: AB 2601 and concurrent lot-split processing
Research checked October 21, 2026 against the chaptered California bills. This series explains signed legislation for 2027 planning, not permission to start work today. General educational information, not legal advice. Confirm the applicable law, permit pathway and property conditions with the reviewing agency and qualified professionals before committing to a project.