Factory-built housing: building standards and local requirements

The law aims to make factory-built housing easier to use statewide by requiring local governments to follow state building standards. It preserves narrowly justified local changes for health and safety conditions.

What the law does ​

• Bars cities, counties, cities and counties, and districts from applying factory-built-housing building standards that differ from or exceed mandatory California Building Standards Code requirements.
• Bars local energy-efficiency and green-building amendments that exceed state mandatory minimums for factory-built housing structures.
• Allows cities and counties to modify state requirements only after publicly finding the change is needed for minimum health and safety because of local climatic, geological, or topographical conditions, including wildfire or flood risk, and filing it with the California Building Standards Commission.
• Creates a presumption favoring decisions that facilitate factory-built housing and project qualification, unless written evidence shows conflict with state standards or a specific adverse health or safety impact.
• Defines factory-built housing structures as residential buildings with at least two-thirds residential new or converted square footage and at least 30% of their residential portion built with factory-built housing.
• Updates related definitions and conforming tax and vehicle-code provisions.

Who it affects ​

• Factory-built housing manufacturers, builders, developers, designers, and purchasers.
• Cities, counties, cities and counties, districts, and local building officials.
• Residents and owners of projects using factory-built housing.

Context ​

The law applies statewide, including charter cities, because the Legislature declared adequate housing a matter of statewide concern.