State law HB 2928 requires counties to expand accessory dwelling unit allowances; Coconino staff to update zoning

Community Development staff told the commission that the state legislature passed HB 2928 and the law requires counties to update their zoning ordinances to increase the number of accessory dwelling units (ADUs) permitted in single‑family residential zoning districts.

Key points from staff Jess McNeely said the county previously permitted ADUs by right in single‑family residential districts and is ahead of many jurisdictions, but the new law requires additional allowances: for parcels under one acre, the statute requires one attached ADU plus one detached ADU; for parcels of one acre or larger the statute allows one attached ADU, one detached ADU and an additional detached ADU (the law provides flexibility and the county may impose certain limitations on that additional entitlement). Reduced setbacks and size‑ratio rules apply per the statute and counties must conform by Jan. 1 (staff said the county has that deadline and will return with ordinance amendments).

Next steps Staff said they will bring zoning‑ordinance updates to the commission for study sessions and public hearings and that some elements are mandatory while others allow local flexibility; formal ordinance changes must be in place by the state deadline.

Why it matters ADU changes could affect housing supply and site design in single‑family areas across the county; staff said accessory‑unit permits typically do not come to the commission because ADUs have been permitted by right but noted the change will require code updates.