Step by step

Add an accessory dwelling unit (ADU) to your property

Learn about adding accessory dwelling units (ADUs), in-law units, or cottages to residential properties.

Many single- and multi-family homes in San Francisco can now add units. You can use the space for family members or to rent for extra income.

This process may take more than 18 months from when you decide to build. 

It typically costs more than $125,000 in materials and labor to add a unit. Professional services for architects and engineers are typically 10% of construction costs. City fees range from 6 to 9% of construction costs. Your total cost can range widely depending on the specifics of your lot and project.

Your property and project plans affect what processes you must follow to get a building permit. Projects may be longer if they include multiple ADUs, seismic work, variances or a Certificate of Appropriateness.

If your project is only for an ADU, follow this process to start your application online. 

Do not use this page for unit legalization or new construction of more than an ADU. If your project includes demolition, you will also need to follow the in-house review process with the Department of Building Inspection

1

Check if you can add new units to your residential property

Cost:

Free

Time:

30 minutes

Decide if an ADU is right for you. Check to see if you can add an ADU at your address. Find out what you can build in your lot.

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2

Design your ADU

Cost:

Free

$10,000+

Time:

1 to 3 months

ADU plans must follow City codes for neighborhood development and building safety. 

Homeowners usually hire an architect or designer to create the plans.

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3

Check our street tree rules

Cost:

Free

Time:

1 to 2 hours

Your property must have 1 street tree per every 20 feet of frontage that borders the public right of way, or pay a tree in-lieu fee of $2,193.

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and

Check rules for adding an ADU to a building with tenants

Cost:

Free

Time:

1 hour

If you are using the Local ADU program and you have tenants, follow these rules.

Check rules for adding an ADU to a building with tenants

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4

Create your plans

Time:

1 or more hours

Create your plans

Follow these rules to create your plans. Create your plans

Add ADU details

You must add details like street tree location to your plan sets for ADUs. See the complete list. Add ADU details to your plan set

Format your PDFs

Format PDFs of your plans for Bluebeam, our electronic plan review software. Format PDFs of your plans

Add our Back Check page

You must add our Back Check Page PDF to submit plans in Bluebeam. Add our Back Check Page to your plans

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5

Fill out paper forms

Time:

1 to 2 hours

You must upload these forms with your application.

Planning forms

Agent authorization form

Download and fill out the Agent authorization form. Do not fill out the Building permit number. 

You must sign this form and upload it with your application.

Fixture Count form

Download and fill out the Fixture Count Form.

Decide you will be applying for additional water meters and note it on your form.

Green energy form

If your project adds less than 1,000 square feet, you can sign the form yourself. If it is more than that, it must be signed by a licensed design professional.

Fill out the Green Energy forms

School Facility Fee form

Fill out the School Facility Fee form

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6

Start your ADU application

Cost:

Free

Time:

1 hour

If your project is only for an ADU and work related to ADU construction, start your application online.

You must upload your plans with your application.

After you apply, we will send you a confirmation email with your application information.

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and

Apply for your street tree permit

Cost:

Free to apply for your street tree permit. If you choose to pay the in-lieu fee, it will cost $2,193 per tree.

If you have not applied for your street tree permit yet, apply now.

Upload this checklist with your tree planting application. You must fill this out even if you will not plant new trees.

Start your tree planting permit application with Public Works

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and

Register to track your construction waste

Time:

30 minutes

You must track your construction waste if your project is for:

  • New construction
  • Additions greater than 1,000 square feet
  • Remodels or alterations that cost $200,000 or more
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7

Staff ADU application intake

Time:

2 weeks

We will review your application and email you within 2 weeks.

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and

Apply for your Street Improvement permit

If you are changing curb cuts, apply for your Street Improvement Permit after you receive your building permit application number.

Apply for your Street Improvement permit.

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8

Pay fees

Cost:

6 to 9% of building costs

We will tell you what your initial fee is.

You must pay your fees online. We will send you instructions.

Respond to plan checker comments

We will invite you to a Bluebeam session to review our comments. Bluebeam is our plan review software.

You may need to make changes to your plans and resubmit them. 

Learn how we use Bluebeam

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9

Complete legal notices

Cost:

$100+ (depending on number of parcels and sheets)

Complete your Notice of Special Restrictions (NSR)

All ADUs must complete a Notice of Special Restrictions (NSR). 

Your planner will work with you to write and complete your NSR.

For State ADUs, you will record the NSR at the City Assessor’s office.

The NSR must be recorded before we can issue your permit and your construction starts.

Complete your Costa Hawkins agreement

ADUs approved under the Local program must complete a Costa Hawkins agreement. 

We will record the NSR and the Costa-Hawkins on your behalf. Both must be recorded before we can issue your permit and your construction starts.

Complete your Costa Hawkins agreement

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10

Permit approval and final fee payment

Cost:

Remaining fees

All City departments have to approve your permit before we can issue your construction document.

We will tell you what your final fee is. You may pay your fees online. We will send you instructions.

We will email you the final documents.

You do not need to pick anything up in person.

(If you submitted a site permit, we will email you instructions to submit your addendum online. You can start construction once your addendum is issued.)

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11

Start construction

You must have your construction document before you can start construction. 

Post your construction document at the construction site.

Call or email us to schedule the appropriate inspections during your construction project.

Other permits

Street space

Once you have your construction document, apply for your street space permit to use street space during construction.

Apply for your street space permit

Trade permits

Once you have your construction document,  you must apply for trade permits, like plumbing and electrical.

You will need to apply for separate permits to:

New water line installation

Once you have your construction document, we will tell you if you need to apply for a new water line or increased capacity.

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Last updated October 14, 2021