Montebello

Montebello allows ADUs and JADUs on residential properties in compliance with California state law. For single-family properties, the city permits one ADU and one JADU. ADUs may be newly constructed, attached, detached or created through conversion of existing space such as garages. 

ADUs must provide independent living facilities and comply with development standards such as setbacks, height and separation requirements.

• Detached ADU: New construction, garage conversions, or units above detached garages
• Attached ADU: Attached to the primary dwelling or converted from existing space
• Conversion ADU: Conversion of existing garage or interior space
• Junior ADU (JADU): Located within the primary residence, up to 500 sq ft

• Maximum Size:
  
  • Detached: Up to 1,200 sq ft
  • Attached: Up to 1,000 sq ft or 50% of the primary dwelling, whichever is less
    
    
• Setbacks:
  
  • Minimum 4-foot side and rear setbacks for new detached ADUs; conversions may follow existing structure setbacks
    
    
• Height Limits:
  
  • Detached: Maximum 16 feet (up to 18-20 feet if near transit or to match roof pitch)
  • Attached: Maximum 25 feet
    
    
• Parking Requirements:
  
  • One off-street parking space per ADU is typically required
  • Parking is not required if the ADU qualifies for state exemptions (e.g., within ½ mile of public transit, located in a historic district, or part of an existing structure conversion)
  • Parking spaces may be located in driveways or setback areas and can be configured as tandem parking
  • Some city planning documents indicate that off-street parking requirements for ADUs have been eliminated, reflecting alignment with state law exemptions

• ADUs are reviewed ministerially (no discretionary approval required) per state law standards referenced in the city materials
• Building permits and plan review are required prior to construction
• Applicants must submit required application forms and construction plans through the Planning Division
• Projects are subject to building and fire safety review and inspections

Homeowners should also review Montebello current fee schedule, utility connection requirements and fire code compliance.

ADU permit timelines in Montebello follow California state law, which requires approval of complete applications within approximately 60 days. 

In practice, total processing time (including plan check and revisions) is typically around 3 to 4 months, depending on application completeness and review cycles.

Engaging professionals familiar with Montebello ADU process can help streamline approval and potentially reduce delays.

ADUs are allowed on lots with an existing single-family dwelling. One ADU (attached or detached) and one JADU are permitted per lot. If multiple single-family dwellings exist on a lot, only one ADU is allowed for the entire lot.

For the most current and complete information, refer directly to the City of Montebello.

ADU regulations are constantly evolving and may vary by city, county, or even neighborhood. Before starting your project, it’s always best to consult with a trained professional or certified ADU Specialist to ensure your plans align with current local requirements.