Number of ADUs Allowed in Montebello
- Maximum size: 1,200 sq ft (detached or attached, or 50% of the size of the main dwelling)
- Side/rear setbacks: 4 feet
- Two story: Yes, for both attached and detached ADUs
- Building separation: 6 feet
- Soils Report: Possibly, especially in areas with grading or on hillsides
- Building Verification Survey: Yes
- Coastal permit (in some areas): N/A
- Stormwater Mitigation: Yes
Number of ADUs Allowed in Montebello
You are allowed to put one attached or detached ADU on single-family property in Montebello, as well as one JADU.
Multifamily property owners in Montebello may convert existing uninhabitable space into at least one attached ADU, and additional ADUs not to exceed a maximum number equal to 25% of the existing units. Ergo:
- From 2 to 7 units, you could convert existing uninhabitable space into one ADU
- From 8 to 11 units up to 2 ADUs
- From 12 to 15 units up to 3 ADUs
- And so on.
No more than two detached ADUs may be constructed on a multifamily lot in Montebello.
ADU Montebello – Size & Building Constraints
An detached ADU can be up to 1,200 square feet in Montebello.
An attached ADU in Montebello can be up to 1,000 square feet, or 50% of the square footage of the primary dwelling unit, whichever is smaller.
In Montebello, an ADU is limited to 16 feet of height.
Due to height restrictions, 2-story ADUs are not allowed in Montebello.
Generally speaking, in Montebello detached ADUs cannot be stacked one on top of another, with one ADU on each story. Only one detached ADU is allowed on single-family property, and even on multifamily property height restrictions would prohibiti such a design.
Montebello rules do not specify whether two detached ADUs can be attached together within one structure, nor does California state law. Keep in mind that only multifamily property is allowed to have two detached ADUs on one property; single-family property is limited to one detached ADU. Plansmightget approved on multifamily property for two ADUs in one detached structure, but other ordinances for landscaping, setbacks, and separation. In practice, it is rare.
No, a JADU is defined as an ADU converted from existing space within the main structure of the primary dwelling unit. As such, it cannot be attached to an ADU.
Generally roof decks would be permitted on an ADU, but must meet the height restrictions for the zone. Roof decks cannot encroach into the required setbacks. As a rule of thumb, railings and access staircases above 42″ need to be included in height calculations.
An ADU must match or harmonize with the exterior of the main dwelling unit, including color palette, roof pitch, architectural style, and other aesthetic characteristics.
ADU Setbacks in Montebello
ADUs behind the primary dwelling unit in Montebello require a minimum of 4-foot side and rear setbacks.
The ADU must maintain sufficient distance from other structures on the property to comply with fire regulations — usually at least 4 or as much as 6 feet of separation between buildings.
City regulations do not explicitly prohibit an ADU in the front yard, but in practice it is very difficult, since the ADU must comply with front and side setback, building, landscaping, and aesthetic requirements.
ADU Setbacks in Montebello
No, you can submit plans electronically using theCity of Montebello GoPost online system.
Montebello may require a soils report for ADU permitting to make sure the soil can support the new structure, especially if the ADU will be located on a hillside, an area with significant grading, or if there are special foundation requirements.
Specific requirements are not mentioned in the building code, but the building plans must allow for sufficient green space and permeable landscaping surface.
The plan check requires a review by the Planning Division for zoning, building standards, and safety compliance. Turnaround times are not specified, but expect the process to take a matter of weeks.
Parking for Montebello ADU
One new parking spot is typically required to be added to the lot per new ADU. However, exemptions may apply if:
- The ADU was built into an existing structure.
- The property is located within a historic district.
- The property is located within ½ mile walking distance of a public transportation stop.
- The property is located within one block of an established vehicle share stop.
- Off-street parking permits are required but not offered to ADU occupants.
If a parking space must be added, it can be included on the driveway or any setback areas, and it may be configured as tandem parking.
Additional Requirements in Montebello
Per Title 24 of the California Energy Code, solar panels of appropriate size and capacity are mandatory on new-construction ADUs. ADUs built from converted existing structures are exempt, as may be ADUs located under significant shading. Smaller ADUs may be subject to reduced or modified solar panel requirements.
An ADU is not required to have a separate water or electrical meter. You can opt for the ADU to share service with the main dwelling unit. However, you can request separate water or electrical meters from the City of Montebello.
Montebello does not automatically assign a new ADU its own address. However, it may assign the ADU a new address if it is intended for rental or independent occupancy. The ADU will usually get a “½” designation — for example, an ADU located behind 1234 Pine Street would have the address “1234½ Pine Street.
Low Impact Development (LID) is an approach to land development or redevelopment that seeks to preserve and conserve onsite water quality and natural features, with minimal detrimental effect to local waterways and ecosystems. The City of Montebello may require LID fees for larger ADUs.
Yes, you can use your ADU as an Airbnb in Montebello, but the primary dwelling unit must be owner-occupied and you can only rent it out for 180 days per year, maximum, according to city ordinances. California state law limits short-term rentals to 30 days at a time and 120 days out of the year. You must be licensed and registered, and additional fees and taxes may apply.
Montebello does not have its own rent stabilization ordinance. Residential rents in the city are governed by the statewide California Tenant Protection Act (AB 1482), and the city directs residents to state and Los Angeles County programs for rent increase and eviction questions.
Under AB 1482, housing with a certificate of occupancy issued within the last 15 years is exempt from the Act's rent cap, which covers newly built ADUs. If the primary dwelling on your property is itself subject to rent control, get confirmation in writing before renting the ADU.
While encouraging the use of electric appliances for efficiency and sustainability, Montebello does not prohibit gas appliances in new ADUs as long as all relevant installation and safety standards are met.
In Montebello you are only required to install sprinklers in a new ADU if the primary dwelling unit has them as well. You may also be required to install them if the ADU is located within a special fire hazard zone.
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