Comprehensive Guide to Obtaining an ADU Permit

Accessory Dwelling Units (ADUs), also known as granny flats, in-law suites, or backyard cottages, are becoming increasingly popular as a way to provide additional living space and increase property value. However, before you can build an ADU, you’ll need to navigate the permit process. This comprehensive guide will walk you through the steps and considerations for obtaining an ADU permit.

Understanding ADUs

Before delving into the permit process, it’s important to understand what ADUs are and why they are beneficial. ADUs are secondary housing units built on the same property as a primary residence. They can be used for various purposes, including housing elderly family members, generating rental income, or providing a private space for guests.

Step 1: Research Local Regulations

The first step in obtaining an ADU permit is to research the local regulations and zoning laws in your area. ADU regulations can vary significantly from one municipality to another, so it’s crucial to understand the specific requirements for your location. Key aspects to research include:

1. 1. Zoning Laws

   • Zoning Designation: Determine your property’s zoning designation (e.g., residential, mixed-use). ADUs are typically permitted in residential zones but may have specific restrictions depending on your municipality.
   • ADU-Specific Regulations: Some areas have dedicated sections in their zoning codes specifically for ADUs. Look for information on unit size limits, occupancy restrictions, and setbacks1.
   • Special Zones: If your property falls within a historic district, environmentally sensitive area, or an HOA, you may encounter additional requirements.

   2. State Law

   • Statewide Regulations: Some states have passed legislation to streamline the ADU approval process and override restrictive local ordinances. For example, California and Oregon have ADU-friendly legislation that makes it easier to add these units3.
   • Owner-Occupancy Requirements: Check if your state has any owner-occupancy requirements, meaning the property owner must live on-site.
   • Maximum Size: States may have specific size limits for ADUs, often based on a percentage of the main dwelling’s square footage or a maximum square footage (e.g., 900 square feet).

   3. Local Ordinances

   • Parking Requirements: Some areas require additional parking spaces for ADUs. Make sure to understand these requirements.
   • Occupancy Rules: Research any occupancy rules, such as whether the ADU can be rented out or must be occupied by a family member.
   • Environmental or Conditional Use Permits: If your property is in an environmentally sensitive area (like a floodplain), additional permits or environmental assessments may be required.

   4. Permit Application Process

   • Permit Types: Understand the different types of permits you may need, such as building permits, electrical permits, and plumbing permits.
   • Application Fees: Be aware of any application fees associated with submitting your permit application.
   • Supporting Documents: Gather necessary documents like a site plan, ADU design plans, proof of property ownership, and any relevant approvals from homeowners’ associations.

Step 2: Consult with Your Local Planning Department

Once you have a good understanding of the local regulations, it’s a good idea to consult with your local planning department. They can provide you with specific information about the permit process, answer any questions, and ensure you have all the necessary documentation. This step can help you avoid potential pitfalls and streamline the application process.

Step 3: Prepare Your ADU Design

Before you can apply for a permit, you’ll need to have a detailed design for your ADU. This design should include:

1. Site Plan: A site plan shows the layout of your property, including the location of the primary residence, the proposed ADU, and any other structures. It should also indicate setbacks and distances to property lines.
2. Floor Plan: A floor plan provides a detailed view of the interior layout of the ADU, including room dimensions and the placement of doors, windows, and fixtures.
3. Elevations: Elevation drawings show the exterior view of the ADU from all sides, including height and architectural details.
4. Construction Details: Include detailed information about the construction materials and methods you plan to use.

You may need to hire an architect or designer to create these plans, especially if you are not experienced in drafting construction documents.

Step 4: Submit Your Permit Application

With your design plans in hand, you can now submit your permit application to the local planning department. The application will typically include:

1. Completed Application Form: Fill out the permit application form provided by your local planning department.
2. Design Plans: Submit the site plan, floor plan, elevations, and construction details.
3. Supporting Documents: Include any additional documents required by your local regulations, such as proof of property ownership, photos of the existing property, and any relevant approvals from homeowners’ associations.

There may be application fees associated with submitting your permit application, so be prepared to pay these fees at the time of submission.

Step 5: Review and Approval Process

After you submit your application, the planning department will review your plans to ensure they comply with local regulations. This review process can take several weeks to several months, depending on the complexity of your project and the workload of the planning department.

During this time, the planning department may request additional information or revisions to your plans. Be prepared to make any necessary adjustments and respond promptly to any requests.

Step 6: Obtain Building Permits

Once your ADU permit application is approved, you’ll need to obtain building permits before construction can begin. Building permits ensure that your ADU will be constructed safely and in accordance with local building codes. The building permit process typically involves:

1. Building Permit Application: Submit a separate application for building permits, which may include additional fees.
2. Inspections: Schedule and pass various inspections throughout the construction process to ensure compliance with building codes.

Step 7: Start Construction

With all the necessary permits in hand, you can now begin construction on your ADU. Throughout the construction process, make sure to adhere to the approved plans and schedule inspections as required by your local building department.

Step 8: Final Inspection and Approval

Once construction is complete, schedule a final inspection with the building department. The inspector will ensure that the ADU has been built according to the approved plans and meets all safety and code requirements. After passing the final inspection, you’ll receive a certificate of occupancy, allowing you to use the ADU.

Conclusion

Obtaining an ADU permit involves several steps, from researching local regulations to submitting detailed design plans and obtaining building permits. While the process can be complex, careful planning and consultation with your local planning department can help ensure a smooth and successful project. By following this comprehensive guide, you can navigate the permit process with confidence and create a valuable and functional living space on your property.