ADU Process

How to Submit Plans for Pre-Approval

Complete and submit a Building Permit For Pre-Approved Vendor Application along with proposed  pre approved ADU plans.

The following items, depending on the actual project, must be provided to the Building Department at the time of plan check submittal. Incomplete plans may be returned as incomplete without review. All documents must be submitted to The Building Department ePlan Submittal Portal.

For Building Permits provide: Digitally submit a Building Permit Application form and Square Footage Worksheet And all construction documents/Plans (All plans shall be 1/4” = 1’, (smaller scales may be approved on a case by case basis) and Construction documents inc. Plans, related studies and calculations must be signed by the designer responsible for that document) 

Plans Must Include:

__  The Cover Sheet must contain all of the following information: Complete Design Criteria; Occupancy Type; List all Special Inspections; List all Deferred Submittals, Plan Index of all sheets included in the plan set; Designer’s name, address, and contact information;  Indicate if the structure has, or will have, residential fire sprinklers. 

__ Zoning, setbacks, buildable area, and building heights 

__ In addition to Planning allowable area calculation, actual structure square footages are required;        

__ Each plan sheet must be signed by the designer, architect, engineer, for preparing the plans. 

__  Roof Plan; Floor Plan; Foundation Plan; Elevations 

__  Building Sections, including all construction details and shear transfer 

__  Door and Window schedules, including U-factors coordinated with the energy documents 

__ Structural Plans, three complete sets, and two sets of calculations and trusses, as applicable 

__ Geotechnical Report, one copy of the report and one copy of the letter from the geotechnical engineer stating that they have reviewed the project plans and have found that the recommendations from the Geotechnical Report have been properly incorporated into the project plans. 

__  Electrical Plans: switches, plugs, lights, fixture and equipment locations and layouts. Wire size, conduit size, panel calculations, single line drawing service and feeders are required for commercial projects and maybe be required for complex residential projects. (See “Deferred Submittal and Permit Guidelines” for services over 600 amps which applies to residential work). 

__ Mechanical Plans: layouts must include equipment locations, duct sizing, register size and locations, combustion air, radiant heating boiler locations, tubing sizing and layout, etc.  (See “Deferred Submittal and Permit Guidelines” for duct sizing and designs). 

__  Plumbing Plans: fixture layout, water, DWV and gas pipe sizing.  

(See “Deferred Submittal and Permit Guidelines” for Gas Pipe Sizing), Water supply pipe material and size, drainage waste & vent pipe material and size, isometric drawings are required for Commercial and are generally required for complex residential projects.  

__  Title 24 Energy Calculations with all required features called out on the plans 

__  California Green Building Code Mandatory Measures (No point system or Tiers required). 

__  Completed Special Inspection Agreement Form (available online) 

Upon towns approval of vendors pre-approved ADU plans, the town will place on its website a brief description of the pre-approved ADU plans along with the contact information of the vendor. This will allow the vendors pre-approved plans to be found by the town residents/ applicants seeking options for pre-approve ADU’s.

Per Assembly Bill No.1332 Section 65852.67 (4)(ii) The posting of a preapproved accessory dwelling unit plan pursuant to clause (i) shall not be considered an endorsement of the applicant or approval of the applicant’s application for a detached accessory dwelling unit by the local agency.

Questions about the process or to schedule pre submittal meeting. Call 650-752-0560 to speak with city staff regarding your proposed pre-approved ADU submittal. In some cases, it is beneficial to request a meeting to discuss your proposed pre-approved ADU plans prior to Submittal.

For Applicants | Homeowners

Understanding the pre-approved ADU plan process is key to a successful permitting process, all applicants / homeowners are encouraged to review the following  ADU requirements.

•    https://www.ci.atherton.ca.us/651/Accessory-Dwelling-UnitsADU

•    https://www.hcd.ca.gov/sites/default/files/docs/policy-and-research/ADUHandbookUpdate.pdf 

•    San Mateo County - ADU Resource Center - https://smcadu.org/

Items required at time of permit application to be considered a complete application:

__ Complete Site Plan showing all setbacks form property lines, structures and trees. 

__  Construction, Operations, and Parking Plan (COP) 

__  Tree Protection Plan; Note: Prior to permit issuance Tree protection must be installed and inspected  

__  Demolition Plan, if applicable, for additions or remodels; Note: For complete demolitions see the demolition checklist! 

__  Authorization form from Designer indicating that applicant is ok to proceed using  pre-approved ADU plan: Please include name of applicant, address of owner, name of ADU, Signature or Seal of the Designer.

__ Geotechnical Report, one copy of the report and one copy of the letter from the geotechnical engineer stating that they have reviewed the project plans and have found that the recommendations from the Geotechnical Report have been properly incorporated into the project plans or provide completed Soils report Waiver Request.  https://www.ci.atherton.ca.us/documentcenter/view/1835 

__ Menlo Park Fire Protection District Approval letter 

__ School district notification indicating that impact fees have been paid or waived 

__ BAAQMD (“J Number”) required for projects that include demolition

__  New address assignment request and notification. ADDRESS-ASSIGNMENT-REQUEST-FORM_2024

When needed, the following will require a separate submittal package: 

__ Grading Permit – (Complete the Grading Submittal Checklist. If a permit is required a complete separate submittal is also required, including 1 set of civil plans and 1 full set of related studies and calculations.) 

__  Landscape Screening Plan: Can be deferred to framing inspection. (Deferral Request Form) 

__  WELO (Water Efficient Landscaping plan): Can be deferred up to time of landscape or irrigation installation. (Deferral Request Form) 

•    See the “FAQ - What needs a Separate Permit”  

•    See “Deferred Submittal and Permit Guidelines” 

•    Contractor Requirements for a Building Permit:  

__ A Town of Atherton Business License is required for the Primary Contractor prior to permit issuance. Note: A Town of Atherton “Subcontractor List” must be completed prior to the final inspection to ensure that all subcontractors have a town business license. This form is available on our website. 

__ Contractor information including license number, contact information, email and worker’s compensation insurance information is required. 

•    Other Agencies Approval/Acknowledgement. After submitting directly to the agency, provide one copy of the approval or acknowledgement letters for: 

__ Menlo Park Fire Protection District Approval letter  

__ School district notification indicating that impact fees have been paid or waived 

__ BAAQMD (“J Number”) required for projects that include demolition 

__ CalWater

•    Permit Applications, Fees & Forms: https://www.ci.atherton.ca.us/153/Permit-Applications-FeesForms  

•    Other Permit checklists are available at: https://www.ci.atherton.ca.us/154/Submittal-Checklist  For General Demolition Permits, Pool Demolition, Water Wells, Grading and Drainage, Generators, Landscape Screening, WELO and Swimming Pools