Preapproved ADU Program

A preapproved accessory dwelling unit (ADU) is a detached, new construction ADU prepared by a third-party qualified professional located on a single-family or multifamily residential property that has been preapproved by the City for compliance with local building and fire code requirements, including the City's Reach Code requirements. Later, site-specific information with the preapproved ADU building is then submitted to the City for building permit issuance, resulting in a quicker permit review since the ADU building has already been approved and only site and utility information is being reviewed.

A permit is required for a preapproved accessory dwelling unit, which must be obtained prior to the start of construction. The following is required to be submitted:

1. A copy of the preapproved ADU building plans by the City of Mountain View.
2. A completed Preapproved ADU Information Form on your project.  
3. A site plan showing the site-specific information, project/zoning data, and utility connection.
4. A Title 24 Energy Report, if not included in (or altered from) the preapproved ADU.
5. A site survey prepared by a licensed civil engineer or land surveyor is required for structures within 6’ of a property line or required setback. You must provide a site survey certificate and obtain approval from the City prior to the concrete pour for the foundation or footings. Present the wet-signed certificate to City Building Inspector for verification at site inspection.
6. Provide a completed Change of Address Request Form.

Permit Required

A building permit and a demolition permit are required. No planning permit is required.

Additional permits that may be required, depending on the scope of work:

• An excavation permit for a new or upgraded utility connection or construction in the public right-of-way, such as the sidewalk, driveway approach.
• A fire sprinkler permit, if the main house or unit has fire sprinklers.
• A new water and/or sewer connection application if upgrading the water or sanitary sewer lateral.

Cost

Typical permit fees (including inspections): $7,000 to $13,000, which is based on a construction valuation (cost of labor and materials) range of $100,000 to $300,000, and, if applicable, an excavation permit fee of up to $12,000, depending on the amount of utility improvements and construction in the public right-of-way.

Timeline

Typical Time to Receive Permit: 30 days 

Process

1. Submit for a building permit online. 
2. After your submission (during prescreen), City staff will contact you with the fee amount owed, based on your project scope, and instructions for online fee payment.
3. With confirmation of payment, City staff will review your permit application in 7 business days and verify your application is complete and code compliant. If any information is determined to be incomplete or incorrect during the initial plan check, City staff will provide you comments and ask you to resubmit. 
4. You will need to reply to the city's comments with revised information or missing materials as part of your resubmittal online.
5. City Staff will review your resubmittal in 7 business days to confirm you have addressed all of the City comments.  
6. Additional permits may be required from the City for your project, including:
   
   1. A fire sprinkler permit to install a new, or modify an existing, fire sprinkler system in the ADU. This permit can be obtained after you receive your building permit, during the construction of your project.
   2. A demolition permit can be submitted at any time during your building permit but you must receive the demolition permit before you start construction or demolition activity.
   3. An excavation permit for any new or upgraded utility connection or for construction work in the public right-of-way. This permit must be obtained in tandem with obtaining your building permit.
7. Set up your account in the Construction and Demolition Waste Tracking system. If you have questions regarding Construction and Demolition Waste Tracking & Diversion Requirements, please contact Public Works at 650-903-6311 or public.works@mountainview.gov.
8. Once you have a complete and compliant permit, the city will issue you a building permit. This allows you to start construction of your project.
9. During construction, your contractor can schedule City inspections online at each stage of construction.
10. On-site inspections are completed by a City Building Inspector. If a Fire permit or Public Works permit is required for your project, inspections are conducted by each Department separately. The building permit is finaled and occupancy of the new ADU is granted upon completion of construction and a final inspection by the City Building Inspector.

Zoning Standards

The same zoning standards apply to all ADU's, including preapproved ADUs. See zoning information on main ADU webpage. 

Requirements

Building Plan Sheet Organization 

The following information must be included in your building plans in the following order:

• Cover sheet
• Blank sheet (page 0) titled "City Approvals"
• Dimensioned site plan
• Demolition plan
• Preapproved Plan Set
• Include the Blueprint for a Clean Bay
• Title-24 energy calculations, if applicable

For Vendors

For vendors interested in joining the City's Preapproved ADU program, please contact the Building Division at building@mountainview.gov or 650-903-6313. All preapproved ADU plans are posted on the City's ADU Accelerator webpage.