Housable
What are the requirements to build ADU in Hidden Hills?
Building an ADU in Hidden Hills enables you to expand your living space and support multigenerational living or provide a separate space for aging in-laws. For a successful project, it's essential to understand Hidden Hills' local regulations and thoroughly evaluate the financial aspects of construction. This guide offers comprehensive insights into Hidden Hills' ADU regulations and key financial considerations, helping you plan and execute your project effectively.
ADU regulations for properties with a single-family home
How many ADUs can you build in Hidden Hills?
In Hidden Hills, only one ADU is allowed within a single-family dwelling, whether attached or detached from the primary building.
How large can an attached ADU be in Hidden Hills?
The maximum size for an attached ADU in Hidden Hills is 1,200 square feet, except in the RA-S2 zone, where it can be up to 1,500 square feet.
How large can a detached ADU be in Hidden Hills?
Detached ADUs in Hidden Hills can also be up to 1,200 square feet, similar to attached ADUs. However, in the RA-S2 zone, they can be as large as 1,500 square feet.
Can I build a 2-story ADU in Hidden Hills?
No, building a 2-story ADU in Hidden Hills is not allowed.
Is there a minimum size for an ADU?
No, Hidden Hills does not have a minimum size requirement for an ADU.
Can I convert the existing space to an ADU?
No. In Hidden Hills, you cannot convert existing space into an ADU within single-family homes.
What is the maximum height for an ADU?
In Hidden Hills, ADUs on properties with single-family houses cannot go higher than 18 feet, measured to the peak of the roof. Additionally, you cannot build attached ADUs as a second story of the single-family dwelling or above detached structures like guesthouses or garages.
ADU regulations for properties with a multi-family building
How many ADUs does Hidden Hills allow for multifamily properties?
Hidden Hills allows at least one ADU conversion in a multifamily property or up to 25 percent of the existing units. Additionally, a maximum of two detached ADUs can be constructed.
How large can an attached ADU for a multifamily building be in Hidden Hills?
For a multifamily building, the maximum size allowed for an attached ADU in Hidden Hills is 1,200 square feet. However, in the RA-S2 zone, it can be up to 1,500 square feet.
How large can a detached ADU for a multifamily building be in Hidden Hills?
In Hidden Hills, detached ADUs for multifamily buildings can have a maximum size of 1,200 square feet, just like attached ADUs. However, in the RA-S2 zone, they can be as large as 1,500 square feet.
Can I stack detached ADUs on top of each other?
Currently, Hidden Hills has not addressed the possibility of stacking detached ADUs.
Can I attach two ADUs to each other?
No, attaching two ADUs to each other is not allowed in Hidden Hills. ADUs should only be attached to the primary building.
Can I convert the existing space to an ADU?
Yes, in multifamily buildings, you can convert existing non-habitable space into an ADU in Hidden Hills.
What is the maximum height for an ADU on a property with a multi-family building
The maximum height for an ADU on a multifamily property in Hidden Hills is the same as that for single-family houses, which is 18 feet.
What ADU types are allowed to build in Hidden Hills?
Hidden Hills offers a range of options for building ADUs:
(1) Detached ADU: A completely separate structure from the primary home.
(2) Attached ADU: A unit that is integrated into the existing house.
(3) Converted ADU: Converting underutilized spaces like garages, sheds, or storage areas into functional living spaces equipped with basic amenities such as a kitchen and bathroom.
You have the option to either build a new ADU or alter an existing structure. Repurposing spaces like garages or sheds can help bypass certain zoning restrictions like setbacks and height limits and may allow for small additions. However, renovating older structures may come with unforeseen issues that could drive up costs.
ADU setbacks from the property lines and other buildings
What are the required setbacks for an ADU in Hidden Hills?
In Hidden Hills, ADUs should comply with zoning regulations for front yard setbacks and have a minimum of 4 feet from side and rear lot lines.
What is the minimum distance the ADU must have from the existing structures?
Hidden Hills does not specify a minimum distance for ADUs from existing structures, but many cities typically require at least 6 feet.
Are setbacks required when existing structures are converted into ADU?
No, setbacks are not required when converting existing structures into ADUs in Hidden Hills.
Can I build an ADU in the front yard of my house in Hidden Hills?
Yes, you can build an ADU in the front yard of your property in Hidden Hills, but it should follow the front setbacks of the base zone. However, if the setbacks prevent the construction of a Statewide Exemption ADU, then this type of ADU can be built in the front setback.
Design requirements for ADU
How many bedrooms can an ADU have?
Hidden Hills does not specify a maximum number of bedrooms for an ADU. However, based on the maximum allowable size of 1,200 - 1,500 square feet, an ADU could typically accommodate at least one bedroom.
Does an ADU need to have a kitchen?
Yes, an ADU in Hidden Hills requires a full kitchen for cooking, unlike JADUs, which often have efficiency kitchens.
Does an ADU require independent utility meters?
Yes, if the ADU is built alongside a new primary dwelling, independent utility meters will be needed to supply the ADU with utilities.
What is the minimum ceiling height?
In Hidden Hills, habitable spaces like ADUs follow the minimum ceiling height requirement of 7 feet, as required by the California Building Code.
Find out the maximum ADU size for your property here
The parking requirements for ADU
What is the parking requirement for an ADU in Hidden Hills?
In Hidden Hills, an ADU needs at least one off-street parking space. However, no additional parking is required if the ADU meets certain conditions: it is within a half-mile of public transit, located in a historic district, part of the primary residence or an accessory structure, has no on-street parking permits available for residents, or has a car share vehicle within one block
Where can I have a parking space on my property?
The parking space for an ADU in Hidden Hills can be in a garage, carport, tandem parking on an existing paved driveway, or the rear yard setback on a paved surface, as long as it is not visible from the public road in front of the main dwelling.
How to get permits for your ADU
How long does it take to get an ADU permit in Hidden Hills?
In Hidden Hills, the ADU permit process typically takes about 3.5 to 4 months. Once your permit drawings are ready, you or your architect should submit them for a Plan Check. It’s advisable to arrange a pre-plan check meeting with a planner to ensure the application is thorough before submission.
After submission and fee payment, the city has 60 calendar days to assess whether your application is complete. If no response is received within this timeframe, the permit is automatically approved. If revisions are required, your designer will need to make the adjustments and resubmit the plans. The application should demonstrate compliance with ADU regulations, as missing information alone will not lead to denial. The plan check fee for ADU projects in Hidden Hills is about $3,200.
Does Hidden Hills require in-person submission of plans for an ADU?
No, Hidden Hills doesn't require you to submit plans for an ADU in person. You can apply for plan checks and permits online through the Hidden Hills Permit Center.
Does Hidden Hills require coastal development permits?
No, Hidden Hills does not require coastal development permits.
When do you need a licensed professional to design an ADU in Hidden Hills?
In Hidden Hills, consulting a licensed professional like an architect or engineer is recommended for ADU design, particularly when considering unconventional construction methods.
Cost, financing and market value of ADUs
How much does it cost to build an ADU in Hidden Hills?
Constructing an ADU in Hidden Hills typically costs around $380 per square foot, which includes expenses for permits, architectural design, and engineering services. For instance, building a 900-square-foot ADU would generally cost about $390,000, covering both soft and hard costs.
Is it profitable to build an ADU in Hidden Hills?
To evaluate the financial viability of building an ADU in Hidden Hills, it's essential to compare construction costs with local real estate market values. For example, a 900-square-foot ADU could be valued at approximately $1,350,000. Given the construction cost of $390,000, this suggests a potential return on investment of around 240%.
Additionally, profitability considerations may include potential rental income or the benefits of housing family members on the same property.
Can you sell an ADU in Hidden Hills?
Local agencies in California can create regulations for selling ADUs and primary homes as condominiums while maintaining existing ADU development standards.
In Hidden Hills, the sale of an ADU is governed by local regulations. An ADU can be sold if constructed by a qualified nonprofit, if there is a recorded tenancy in common agreement, or if the city permits the separate sale of both the ADU and the primary home as condominiums.
Are ADUs rent-controlled in Hidden Hills?
No, ADUs in Hidden Hills are not governed by rent control regulations. Landlords of newly constructed ADUs can raise rents annually. Rent control under AB 1482 applies only to buildings that are 15 years or older.
How do I get money to build an ADU in Hidden Hills?
To fund ADU construction in Hidden Hills, consider CalHFA’s ADU Grant Program. This program provides grants of up to $40,000 to cover pre-development and closing costs such as architectural designs, permits, and site preparation, supporting ADU development as part of California's affordable housing projects.
Find out how much value an ADU could add to your property.
Related Articles
ADU Solutions for Aging in Place in Hidden Hills
All You Need to Know About Building on Properties in Hidden Hills Under SB-9
Everything You Need to Know About SB-684 Development in Hidden Hills
How to get your permits fast or the benefits of using SB-423 in Hidden Hills