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Accessory Dwelling Units
Your Accessory Dwelling Unit (ADU) From Start to Finish
The steps for permitting your Accessory Dwelling Unit (ADU) with the City of Modesto are outlined below in eight steps.
1. Create a Plan
The first step is to create a Site Plan which shows your property boundaries, placement and size of:
- Existing House
- All Structures (Detached garage, gazebo and any others)
- Stanislaus County ADU - 260 Square Feet Plans (PDF)
- Stanislaus County ADU - 562 Square Feet Plans (PDF)
- Stanislaus County ADU - 744 Square Feet Plans (PDF)
- Stanislaus County ADU - 798 Square Feet Plans (PDF)
- Stanislaus County ADU - 896 Square Feet Plans (PDF)
2. Get Planning Advice from the City of Modesto
Prior to submitting for a building permit, it is a good idea to check with the Planning Division on Accessory Dwelling Unit (ADU) setbacks and other zoning requirements.
You can check with the planning division by bringing your plans to the Planning and Building counter on the 3rd Floor at City Hall located at 1010 Tenth Street, Suite 3100, Modesto CA 95354.
A Planning Division staff member will advise you on topics including ADU zoning regulations and answer other questions you may have regarding permitting.
Here are some items to note before your visit:
- Save time at the counter by first referring to the Modesto Municipal Code section 10-4.115. Table 4.1-3 at this link provides useful planning information.
- If your ADU will be a second story addition on a garage, and your neighboring properties are all single-story, you may need an administrative review by the Planning Division. View and print the Administrative Application.
- You can also ask questions and share your plans by emailing the Planning Division, or calling the Planning Division at 209-577-5267.
- If you need an address for your ADU, you will also need to apply through the Planning Division. You will need to have your ADU building permit before applying for its own address.
- The fee for a new address is currently $182 and the application should be submitted to the Planning Division, either by regular mail or at the Building and Planning counter.
We are currently collecting Examples of Pre-Approved ADU Plans to share on our website.
3. Prepare Permit Submittal Package
Your submittal package must include:
- Complete set of Plans
- Energy Calculations
- Truss Calculations
- Structural Calculations
4. Apply for your ADU Permit
- For an ADU building permit, you can apply using the City of Modesto eTRAKiT online Permit System, You will need to set up a personal account, then log in and go to Permitting, then Apply for a permit, and select ADU from the drop-down list.
- Review an example of estimated ADU development fees.
5. Hire Experienced, Licensed Professionals
- We advise that you hire a designer, licensed architect or engineer to design your Accessory Dwelling Unit (ADU), and a licensed contractor to build it. Your ADU can be custom designed for your site, use pre-approved plans, or you may want to take advantage of prefabricated units.
- Pay permit fees online with e-check or credit card, or in-person.
6. Your Plans will be reviewed by City Staff
- You can use the City of Modesto's eTRAKiT online Permit System to view progress.
7. Permit Issued
- Your permit will be mailed to you and posted to your eTRAKiT account when you have paid all permit fees. You can pay online through the eTRAKiT system or in-person at the Community and Economic Development counter, 3rd Floor City Hall, 1010 Tenth Street, Suite 3100, Modesto CA 95354.
8. Construct Your ADU, Schedule and Pass inspections
- Log in to your eTRAKiT account to schedule inspection appointments. We recommend you watch the short Inspection Scheduling video first.
Additional ADU Resources
- Get assistance with financing, design, permitting and construction through Stanislaus Equity Partners (STEP).
CalHFA ADU Grant Program
- Accessory Dwelling Unit (ADU) Grant Program | CalHFA
- This grant provides up to $40,000 to reimburse pre-development and non-reoccurring closing costs associated with the construction of the ADU.
San Joaquin Valley Regional Planning Agencies Policy Council (REAP)
- Informational ADU Handout for the General Public
- Fee ADU Housing Plans, and more
California Housing and Community Development Department (HCD)
- Overview of ADU funding programs, current laws, HCD’s ADU Handbook and other ADU resources and information.
White House Briefing - Housing Costs
- President Biden Announces New Actions to Ease the Burden of Housing Costs | The White House
- 2023 Budget to include $25 Billion in federal grants for Affordable Housing Production. This includes intergenerational housing, investments that place vacant or underutilized properties back into productive use, ADUs, and novel and non-traditional development techniques, including modular, panelized, or manufactured housing.