Do you have an unwarranted unit on your property, and you want to legalize it? This is what you need to know and do to legalize your residential unit.

At CityStructure, our vision is a world where every homeowner has a clear understanding of the development potential of their property. This is why we give you free access to the Untapped Development Potential for any property.

Before starting the process of ligalizing un unwarrented unit, you need to know few important conditions:

* The maximum number of the Unwarranted Dwelling Units (UDU) allowed to be legalized.

One unwarranted dwelling unit will be permitted to be legalized on each lot.

* How to convert or remove a unit in an existing building

The unwarranted unit is permitted to expand Within the existing built envelope. However the Planning Code limits the amount of floor area an existing dwelling can be reduced and be added to another dwelling unit. Generally, the floor area of an existing dwelling unit cannot be reduced by more than 25%.

* Legalizing the unit and subdivide it or TIC

Legalized units are ineligible for subdivision, which means they cannot be sold individually.
The legalization program cannot be used to legalize dwelling units that have had owner move-in evictions filed after March 13, 2014 if the notice was served within five years prior to the permit application being filed for legalization; or other no-fault evictions filed after March 13, 2014 if the notice was served within ten years prior to the permit application being filed for legalization.

* Rent control for the newly legalised unit

A dwelling unit that was subject to the Residential Rent Stabilization and Arbitration Ordinance prior to legalization remains subject to that Ordinance after legalization.

* How to merge the legalized unit with another existing unit

You may request to merge the legalized unit with an original unit through the Conditional Use Authorization process, which requires action by the Planning Commission at a public hearing.

In addition to the legal conditions, the new unit has to follow the Planning and Building Code requirements. Here is what you need to know.

Planning Code requirements for unwarrented units

The Zoning Administrator may waive rear yard, parking, open space, density, and the light and air requirements for exposure for the unwarranted dwelling unit proposed to be legalized.
Note that legalizing the unwarranted dwelling unit cannot create or intensify nonconformity for the existing, legal dwelling unit(s) on the property. For example, although the specific square footage for the open space is waived under this program, the addition of a dwelling unit should not remove any existing unit(s) access to shared open space, such as a rear yard. In this scenario, ensure that your plans retain access to the shared rear yard, such as through a common corridor or rear stairs.
All other Planning Code requirements must be met. The most common requirements that must be met for adding dwelling units include bicycle parking, permeability and landscaping in your front setback area, and street trees (under the regulations of Public Works).

Building Code requirements for unwarrented units

All Building Code requirements must be met, including ceiling height, proper ventilation, light, fire safety, and egress.
A pre-application meeting with the Department of Building Inspection and the Fire Department (for three or more dwelling units with Fire) can determine if there are applicable equivalencies for meeting the Building Code. Additional sprinkler requirements on the ground floor.

Process to legalize unwarranted units

1. Get confirmation from the Department of Building Inspection (DBI)

Property owners must start the legalization process with the Department of Building Inspection (DBI). DBI confirms eligibility for enrollment in the legalization program. Review the G-17 Information Sheet, one of DBI’s informational bulletins, for full details on the Unit Legalization program.

2. Complete the Screening Form

Owners may receive an estimation of the costs to legalize their units by undergoing an initial screening process. This screening is an informal consultation with DBI staff, non-binding and free of charge. Here is the Screening Form for more details.

a. Hire a professional representative (engineer, architect, or contractor)

who will be responsible for providing the owner with a professional assessment of what legalization may entail.

b. Home owner must provide documentation that the dwelling unit to be legalized existed prior to January 1, 2013


c. The home owner submits the screening form to DBI,

via email to [email protected] or via mail to 49 South Van Ness Avenue, Suite 500, San Francisco, CA, 94103

3. Two sets of plans are required

Following the screening process, when the owner has essential information needed for a decision, the home owner may then formally apply for a building permit for legalization with the Planning Department and DBI. Here is the permit intake checklist.

Fees to legalize unwarranted units

Legalization permits issued between January 1, 2020, and December 31, 2024 are eligible for a partial waiver of some plan review fees. Check SF Planning dept. fees for current rates. If other scopes of work are required, these should be on a separate building permit in order to obtain the fee waiver for legalization.


Legalization permits CANNOT be issued over the counter. Currently, the permit review process can take 2 - 4 months. Applications that require variances, or a conditional use permit, will likely take six months or more. There is no neighborhood notification requirement for legalizing a unit under this program.

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