Number of ADUs Allowed in Westlake Village
- 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 Westlake Village
You are allowed to put one attached or detached ADU on single-family property in Westlake Village, as well as one JADU.
Multifamily property owners in Westlake Village 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.
Up to 8 detached ADUs can be built on multifamily property, as long as the number of detached ADUs does not exceed the current number of units on the property.
ADU Westlake Village – Size & Building Constraints
A detached one-bedroom ADU can be up to 850 square feet, while a detached two-bedroom ADU can be up to 1,000 square feet.
An attached one-bedroom ADU can be up to 850 square feet, while an attached two-bedroom ADU can be up to 1,000 square feet. In either case, the size of the ADU cannot exceed 50% of the size of the primary dwelling unit.
A detached ADU in Westlake Village can usually be built to a maximum height of 16 feet. If the property is located within ½ mile walking distance of a major transit stop or transit thoroughfare, that limit increases to 18 feet. An attached ADU can be equal to the height of the main dwelling unit, up to a maximum of 25 feet. Conversions of existing spaces into ADUs are not limited by height requirements.
As long as the height requirement is adhered to, nothing specifically prohibits you from building a 2-story ADU. 16 feet is probably too short; an 18-foot structure is about the minimum for two stories.
Since only one ADU is allowed on single-family property in Westlake Village, you cannot have two ADUs stacked one on top of another with one on each story. Stacked ADUs may be permitted on multifamily property if height restrictions and other conditions are adhered to.
Since only one ADU is allowed on single-family property in Westlake Village, you cannot have two ADUs attached to one another in one structure. Detached structures containing multiple ADUs may be permitted on multifamily property.
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. An extension of the MDU like a garage.
ADU Setbacks in Westlake Village
ADUs behind the primary dwelling unit in Westlake Village require a minimum of 4-foot side and rear setbacks.
A detached ADU must be at least 10 feet from other structures and 8 feet from eave to eave.
An ADU can be built in the front yard of a home in Westlake Village as long as it complies with front setback and other requirements.
ADU Setbacks in Westlake Village
Building permits in Westlake Village are actually issued by Los Angeles County. You can submit plans using the EPIC LA online resident portal locatedhere.
Westlake Village 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.
Sufficient green space and permeable surface must be maintained on the property. City regulations do not specify specific percentages and must be approved on a case-by-case basis in the planning stage.
Plans are submitted to the Los Angeles County Building & Safety Department, which checks the plans for compliance with building codes, safety codes, and structural integrity. Turnaround times can vary, but the process takes an average of 2-3 weeks.
Parking for Westlake Village ADU
One new parking spot is typically required to be added to the lot per new ADU. However, exemptions may apply if:
- The ADU construction 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 Westlake Village
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 Westlake Village.
An ADU doesn’t necessarily get its own address, but a separate address can be applied for and may be mandated if determined by the city to be necessary for public safety reasons.
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 Westlake Village may require LID fees for larger ADUs.
You can, but California State Law requires that dwelling units can only be used as short-term rentals or Airbnbs for terms of 30 days or longer.
Per the Costa-Hawkins Act of 1995, Westlake Village does not impose rent control on dwellings constructed after February 1, 1995. This means most new-build ADUs are exempt. However, if the primary dwelling unit is subject to rent control, it might apply to the ADU as well.
While encouraging the use of electric appliances for efficiency and sustainability, Westlake Village does not prohibit gas appliances in new ADUs as long as all relevant installation and safety standards are met.
In Westlake Village 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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