The City of Downey is inviting design professionals to submit construction documents for review to be part of our Pre-approved, detached ADU plan program, in accordance with Assembly Bill 1332. After approval by the applicable City departments, the pre-approved construction documents will be made available for use by property owners within the City. The design professional will still maintain the copyright to their preapproved design, any homeowner who wishes to use their design must contract with them directly to do so. The pre-approved plans are only about 80% complete and will always require property-specific modifications. In addition to the building plans, site-specific land use information will also need to be completed. Once the property owner selects a pre-approved plan, they will work directly with that design professional to prepare construction documents that represent their site-specific factors.

The posting of preapproved detached accessory dwelling unit plans shall not be considered an endorsement of the design professional by the City of Downey.

• The goal of this program is to expedite the Detached ADU permitting process and encourage the construction of accessory dwelling units to support our regional housing goals.

• Please note: this program/Assembly Bill 1332 applies to detached ADU’s only.

1. Plans shall have Pre- Approved Detached ADU Minimum Submittal Requirements, including but not limited to:

   • Architectural plan set to include a title sheet, utility plan sheet.

   • Designs shall be provided with options for the installation of fire rated walls.

   • Designs shall be provided with options for exterior finish materials to ensure architectural compatibility with primary dwelling unit and surrounding neighborhood.

   • Complete plot plan showing setbacks, easements, lot dimensions, distances between

   • buildings, size of building, etc.

   • Structural Calculations, as applicable.

   • Energy calculations.

   • Fully dimensioned floor plan of each level.

   • Fully dimensioned roof plan with referenced construction details.

   • Fully dimensioned foundation plan with referenced construction details.

   • Building cross sections.

   • Building elevations. Show floor and top of roof elevations, natural and finished grade around the perimeter of the building.

   • Door/ window schedule – identify all “Egress” door/windows and all other door/window coordinate onto floor plan.

   • Separate permits are required for grading, photovoltaic systems, and fire sprinklers.

2. The Building Division will then route to each submittal to Building, Planning, Downey Fire Department, and Public Works for review.

3. Upon obtaining approval from all city departments, the design professional will be notified, and the following information will be added to the Building Division webpage:

• Designer contact information (provided by applicant)

• ADU description; dimensions, square footage, etc. (provided by applicant)

• Photos or renderings (provided by applicant)

IMPORTANT: Each standard plan will need to be updated when the City of Downey adopts new building codes, building policies, or zoning regulations.

1. Obtain pre-approval from Planning; bring in a site plan for review by the Planning Division that shows: property layout with the footprints of all existing and proposed structures, electrical services, fences, walls, gates, setbacks, parcel areas, easements, driveways, slopes, drainage for stormwater, and other prominent features of the site.

2. Select a detached ADU from the list of pre-approved plans on the City’s website.

3. Contact the designer of your chosen ADU and work with them to incorporate your site-specific requirements into the pre-approved plan.

4. Submit a Permit Application and pay the site-specific plan review fees at the Building Division.

   • 1-hour fee for the Building, Planning, Downey Fire Department and Engineering Division’s to complete the site-specific plan review.

5. Once fees are paid, the Building Division will route plans to the Building Plan Checker, Planning, Downey Fire Department and Engineering for concurrent reviews.

6. If fire sprinklers are required, they can be a deferred submittal. Please note: all deferred submittals must be submitted, approved, and permitted prior to framing inspection. Framing will not be approved until all deferred submittals are approved.

   • Important: Once the homeowner/applicant has obtained approved for submittal, the applicant will need to submit a New Address Request: Complete this step at plan submittal to avoid delays.

7. Once all City departments have approved the construction documents, the Building Division will approve the plans.

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