Summary:

California’s housing crisis demands bold solutions, but historic preservation laws have often been used to block the development of new housing.  Assembly Bill 1061 (AB-1061), signed into Law in October 2025, modifies the California HOME Act (SB 9, 2021) to allow urban lot splits and duplex development in historic districts—while safeguarding significant historical resources.

Background: SB-9 and Its Limitations

SB-9 legalized ministerial approval for:

• Urban lot splits: Subdividing a single-family parcel into two lots.
• Duplex development: Building up to two units per lot.

This Law aimed to enable up to four homes on lots previously zoned for one, promoting small-scale infill housing.  However, SB 9 excluded historic districts entirely, creating a loophole that opponents exploited to block housing.

What AB-1061 Changes

AB 1061 removes the blanket exclusion for historic districts under SB 9 and replaces it with targeted protections:

Key Provisions

✅ Urban Lot Splits & Duplexes Allowed in Historic Districts

• Permitted if no demolition or alteration of contributing historic structures occurs.

✅ Restrictions on Demolition

• Prohibits projects that would:
• Demolish more than 25% of the exterior wall area.
• Alter character-defining exterior features of a contributing structure.

✅ Historic Resource Safeguards

• SB 9 projects cannot occur on parcels individually listed in:
• State Historic Resources Inventory.
• California Register of Historical Resources.
• Local landmark ordinances.

✅ Local Authority

• Cities/counties may adopt objective standards to maintain the integrity of historic districts (e.g., design guidelines).

✅ Ministerial Approval Timeline

• Applications must be approved or denied within 60 days, streamlining the process.

Impact

• Housing Supply: Unlocks SB 9 potential in historically exclusionary neighborhoods, enabling up to four homes per lot without harming historic character.
• Historic Preservation: Maintains protection for individually listed landmarks and contributing structures.
• Policy Balance: Ends the misuse of historic designations as a barrier to housing while respecting genuine cultural heritage.

Implementation Guide for Local Agencies

·       Update Ordinances

o   Remove blanket SB 9 exclusions for historic districts.

o   Adopt objective design standards for historic areas.

·       Train Staff

o   Ensure planners understand demolition limits and eligibility criteria.

·       Public Outreach

o   Communicate that AB 1061 protects historic resources while enabling housing.

Bottom Line

AB 1061 is a surgical fix: it opens the door for small-scale housing in historic districts without erasing California’s architectural heritage.  By striking a balance between preservation and progress, the Law addresses a key barrier to housing production.