ORDINANCE GUIDEEffective Jul 2025
Caldwell ADU Guide
Summary of Caldwell City Code Title 10 Article 12 (ADU regulations · 2025 update; owner-occupancy removed; 900 sqft / 2BR cap) as it applies in Caldwell. Reference: https://library.municode.com/id/caldwell.
Code evolves continuously. Verify at the official source (https://library.municode.com/id/caldwell) before any development decision.
Renew analysis
Where this pathway usually breaks. And where it actually works.
State law guarantees at least one ADU per lot in Caldwell as of July 1, 2026. No owner-occupancy requirement means investors can hold both units as rentals. Existing HOA bans remain enforceable — verify CC&Rs before acquisition. New subdivisions platted after July 2026 cannot prohibit ADUs without unanimous consent.
Caldwell's ADU framework relies on state preemption rather than detailed local code. Investors must verify size caps, setback requirements, and parking standards directly with the Building Safety Division before underwriting. Lack of explicit local code creates uncertainty — confirm all standards in writing before LOI.