Southland Remodeling
What are the requirements to build ADU in Downey?
Adding an ADU in Downey offers a valuable opportunity to expand your living space and enhance property value and potential resale value. To ensure success with your ADU project, it's essential to understand the local regulations affecting your property and assess the financial feasibility of constructing an ADU in Downey. This guide offers a thorough overview of Downey's ADU requirements and critical financial considerations to help you plan and execute your project effectively.
ADU regulations for properties with a single-family home
How many ADUs can you build in Downey?
In Downey, you can build one ADU per lot with a single-family home, whether attached or detached from the primary building.
How large can an attached ADU be in Downey?
An attached ADU can be up to 850 square feet for a studio or one bedroom and up to 1,000 square feet for a unit with two or more bedrooms. It's also limited to 50% of the existing dwelling's floor area. Still, even with these size limits, the ADU will not be reduced to less than 800 square feet.
How large can a detached ADU be in Downey?
A detached ADU can be up to 850 square feet for a studio or one bedroom and up to 1,000 square feet for units with two or more bedrooms. Regardless of the rules, it can't be less than 800 square feet.
Can I build a 2-story ADU in Downey?
Yes, a 2-story ADU is allowed in Downey, as long as it stays within the two-story limit.
Is there a minimum size for an ADU?
No, Downey has not specified any minimum size requirements for an ADU. However, the Building Code will require a minimum size for each room type to create livable spaces.
Can I convert the existing space to an ADU?
Yes, existing spaces, including parts of a home or accessory structure, can be converted into an ADU. An additional 150 square feet are allowed to fit entrances or exits.
What is the maximum height for an ADU?
A detached ADU can be up to 16 feet in height. However, if located within a half-mile walking distance of a major transit stop or high-quality transit corridor, it can reach up to 18 feet, with an additional 2 feet allowing for roof pitch alignment.
ADU regulations for properties with a multi-family building
How many ADUs does Downey allow for multifamily properties?
Multifamily properties in Downey can have up to two detached ADUs. You can also convert non-livable spaces within the existing building with at least one allowed and up to 25% of the existing units converted.
How large can an attached ADU for a multifamily building be in Downey?
For a multifamily property, attached ADUs can be up to 850 square feet for a studio or one-bedroom, and up to 1,000 square feet for units with two or more bedrooms. The ADU can take up 50% of the existing floor area, but it will not be less than 800 square feet regardless of the limit.
How large can a detached ADU for a multifamily building be in Downey?
A detached ADU on a multifamily property can also be up to 850 square feet for a studio or one-bedroom and 1,000 square feet for larger units. Like with other ADUs, it can’t be made less than 800 square feet.
Can I stack detached ADUs on top of each other?
Downey doesn’t have specific rules on stacking detached ADUs.
Can I attach two ADUs to each other?
No, Downey doesn’t allow two ADUs to be attached to each other.
Can I convert the existing space to an ADU?
Yes, non-livable spaces in multifamily buildings like storage rooms, attics, or garages can be converted into ADUs, as long as they meet state building codes for homes.
What is the maximum height for an ADU on a property with a multi-family building
On a property with a multifamily building, the maximum height for a detached ADU is typically 16 feet. However, if the ADU is within a half-mile walking distance of a major transit stop or high-quality transit corridor, it can be up to 18 feet tall, with an additional 2 feet allowing for roof pitch alignment. If the multifamily building is more than one story above grade, the detached ADU cannot be higher than 18 feet.
For attached ADUs, the maximum height is 25 feet or the height limit of the primary dwelling zone, whichever is lower.
What ADU types are allowed to build in Downey?
Downey permits several kinds of ADUs:
1. Detached ADU: A standalone unit built separately from the primary residence.
2. Attached ADU: An addition connected directly to the main home.
3. Converted ADU: Converting existing non-livable areas, such as garages, sheds, or storage spaces, into a habitable unit equipped with features like a kitchen and bathroom.
You can either build a completely new unit or adapt an existing structure. Converting spaces such as garages or sheds often avoids some rules, including setback and height requirements, and may even allow for minor expansions. That said, older buildings could present unexpected challenges, potentially leading to increased costs.
ADU setbacks from the property lines and other buildings
What are the required setbacks for an ADU in Downey?
ADUs need at least 4 feet of side and rear yard setbacks. Front yard setbacks depend on the zone: 20 feet for R-1 and R-2, 15 feet for R-3 and R-3-O, and no setback in M-U zones.
What is the minimum distance the ADU must have from the existing structures?
While Downey doesn't specify a minimum distance from other buildings, many cities require at least 6 feet between an ADU and any existing structure.
Are setbacks required when converting existing structures into ADU?
No setbacks are needed if you build an ADU using the same location and dimensions as an existing structure in Downey.
Can I build an ADU in the front yard of my house in Downey?
In Downey, placing an ADU in the front yard is allowed if your property lacks sufficient space to accommodate a unit of at least 800 square feet in other areas. However, zoning regulations regarding setbacks should still be adhered to.
Design requirements for ADU
How many bedrooms can an ADU have?
An ADU in Downey can have at least one bedroom, although studio units don’t have bedrooms.
Does an ADU need to have a kitchen?
Yes, an ADU in Downey needs a full kitchen, unlike JADUs, which may have a smaller, efficiency kitchen.
Does an ADU require independent utility meters?
No, ADUs share the same utility connections as the primary residence. Separate meters or utility connections are not allowed.
What is the minimum ceiling height?
The minimum ceiling height for livable areas in Downey, including ADUs, typically complies with the California Building Code, which requires a minimum of 7 feet.
Find out the maximum ADU size for your property here
The parking requirements for ADU
What is the parking requirement for an ADU in Downey?
Downey typically requires one off-street parking space per ADU, but there are exceptions:
- If the ADU is within half a mile of public transit.
- If it's located in a historic or architecturally significant district.
- If the ADU is part of the primary residence or an accessory structure.
- If the area doesn’t offer on-street parking permits to ADU occupants.
- If there's a nearby car share stop.
Where can I have a parking space on my property?
Parking spaces for an ADU can be placed in setback areas or arranged as tandem parking. If a garage, carport, or covered structure is converted to an ADU, you don’t need to replace those off-street parking spaces.
How to get permits for your ADU
How long does it take to get an ADU permit in Downey?
The process of securing an ADU permit in Downey typically spans 105 to 120 days. Once your architectural plans are finalized, they can be submitted for a Plan Check. To streamline the process, consulting with a planner beforehand can help confirm your application is complete.
After submission and fee payment, the city has 60 days to review and determine if the application is complete. If no response is given within this timeframe, the permit is considered automatically approved. If revisions are requested, your designer must update and resubmit the plans. Applications must clearly show compliance with ADU requirements, as insufficient details alone are not valid grounds for rejection. The plan check fee for ADU projects in Downey is approximately $1,086.
Does Downey require in-person submission of plans for an ADU?
No, plans can be submitted electronically through the Accela Citizens Access (ACA) portal starting April 1, 2024. Paper submissions are accepted until fall 2024, after which everything will be done online.
Does Downey require coastal development permits?
Downey does not require coastal development permits.
When do you need a licensed professional to design an ADU in Downey?
In Downey, a licensed professional is required if the ADU design doesn’t follow standard construction methods.
Cost, financing and market value of ADUs
How much does it cost to build an ADU in Downey?
Constructing an ADU in Downey typically costs around $380 per square foot. Alongside construction expenses, it's crucial to budget for additional costs such as permits, architect fees, and engineering fees. For instance, the total expense to build a 900-square-foot ADU averages about $390,000, encompassing both soft and hard costs.
Is it profitable to build an ADU in Downey?
The financial feasibility of constructing an ADU in Downey depends on construction costs and the local real estate market. A 900-square-foot ADU in this area is estimated to have a market value of approximately $540,000. With a total project cost of around $390,000, this translates to a return on investment of about 39%.
Profitability can also be assessed based on potential rental income or the advantages of having family members residing on the same property.
Can you sell an ADU in Downey?
AB 1033 allows California's local agencies to establish rules for selling ADUs and primary homes as condominiums while keeping existing ADU development rules in place.
In Downey, selling an ADU follows local ordinances with certain conditions. The ADU can be sold if it was built by a qualified nonprofit, if a recorded tenancy in common agreement is present, or if the city allows the ADU and main home to be sold as individual condominiums.
Are ADUs rent-controlled in Downey?
No. In Downey, ADUs are not under rent control. Rent control laws typically apply to buildings over 15 years old, and since ADUs are new constructions, they are exempt from regulations like AB 1482.
How do I get money to build an ADU in Downey?
Homeowners can access funds through the CalHFA ADU Grant Program, which offers up to $40,000 for site prep, design, permits, and other upfront costs. To qualify, homeowners need to live on the property and have an income of up to $158,000. They are free to select tenants for the ADU.
Find out how much value an ADU could add to your property.
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