SB 9 Laws in Walnut Creek

April 28, 2022

Learn about Walnut Creek's permanent ordinance on SB 9.

The City of Walnut Creek was quick to pass an urgency ordinance on SB 9. Senate Bill 9 is a groundbreaking California state law that allows homeowners to subdivide their single-family residential property and build two or more units on each lot. While some cities welcome the increased density, others see it as the death of single family zoning and an infringement of the rights of local governments.

Walnut Creek recently adopted a permanent ordinance, replacing the urgency ordinance. Though there are many similarities between the town's urgency ordinance and their permanent one, there are some key differences as well.

To learn more about the ordinance, read relevant news articles, and compare guidelines between cities in Contra Costa County, check out Homestead's SB 9 City Guide for Walnut Creek!

Walnut Creek's SB 9 Laws At-A-Glance



  • Residential use only
  • No short-term rentals (minimum 31 days)
  • 3-year owner occupancy required for lot splits

Demolition/alteration prohibited for the following:

  • Current or former (within the last 3 years) rental housing
  • Registered affordable housing
  • Rent stabilized housing

Allowable units

  • 2 primary units; ADUs and JADUs allowed on intact lots

Lot configuration

  • 1,200 sq ft minimum lot size (following split)
  • Extensive requirements for hillside districts

Development requirements

  • 800 sq ft max. size for all new units
  • 16’ (1 story) height limit for all new units
  • Covered off-street parking required (for properties outside of High Transit Areas)
  • All new utility connections must be installed underground
  • Multiple design requirements; see below for details

To see if your property qualifies for Senate Bill 9, use our free search tool.

Details from Walnut Creek's SB 9 Ordinance

Continue reading below for more information on SB 9 guidelines in Walnut Creek.


In accordance with the state law, SB 9 only applies in Walnut Creek's single-family residential zones. The ordinance defines these as "the Single-Family Residential District (R), the Hillside Planned Development District (H-P-D), and the Single-Family High-Planned Development District 1 (SFH-PD1), and to lots located within the Planned Development District (P-D) where Single-Family Residential District (R) uses are the only allowed uses."

If your property is zoned differently, it’s ineligible for SB 9 development. If you're unsure of your property’s zone, search your address on the town's official Zoning Map.

In the interest of protecting sensitive ecological areas and the species that inhabit them, state law prevents SB 9 development on parcels located within conservation and habitat areas. Historic districts and landmark properties are likewise ineligible for SB 9.

(Very) High Fire Severity Zones, Special Flood Hazard Zones, and Earthquake Fault Zones can be eligible for SB 9, provided the project complies with certain safety requirements. Click on the links above to learn more.


Because Senate Bill 9 was created to help alleviate the housing crisis, all SB 9 units must be limited to residential use only. Short-term rentals are not allowed, and as such all rental or lease agreements must be for a minimum of 30 days.

All urban lot split applicants must agree to live in one of the units as their primary residence for three or more years following the split.

In keeping with state law, no demolition or significant alteration is permissible on current or former (i.e. within the las three years) rental units.

No SB 9 development is allowed on properties where a tenant eviction has occurred within the last fifteen years.

Allowable Units

In Walnut Creek, lots created via an SB 9 urban lot split may have a maximum of two primary dwelling units (either one existing unit and one new SB 9 units, or two new SB 9 units) per lot. The ordinance includes that no accessory dwelling units (ADUs) or junior accessory dwelling units (JADUs) are allowed on the same lot as an SB 9 dwelling unit.

On intact lots (i.e. those that do not utilize the lot split provision), two primary dwelling units are allowed per lot, and ADUs and JADUs are allowed in accordance with Article 5 of Part III of Walnut Creek's Zoning Ordinance.

Lot Configuration

Lots must be at least 2,400 square feet in order to qualify for an SB 9 lot split. Each resulting lot must be a minimum of 1,200 square feet and retain at least 40% of the original parcel's size.

The city does not include any minimums for lot width, depth, or frontage in their ordinance.

Development Requirements

Although the city's urgency ordinance did not include special limits on SB 9 unit size, the permanent ordinance states that new units ay be no larger than 800 square feet. They are also subject to height requirements of 16 feet, and must be one story.

While SB 9 requires that cities allow 4 foot minimum front and side setbacks, the law offers no guidance on front setbacks. SB 9 developments in Walnut Creek must comply with zone standard front and street-side setbacks, and minimum distance between structures must be maintained.


Walnut Creek has chosen to require one covered parking space per unit. In accordance with state law, no parking is required for properties within half a mile's walking distance of the Walnut Creek or Pleasant Hill BART station or a County Connection bus stop with service intervals of 15 minutes or less (during peak hours). Properties within one block of a car share vehicle are also exempt from parking requirements.


All new utility connections must be installed underground.


Walnut Creek's ordinance includes a number of design requirements that impact the following features:

  • Architectural style
  • Exterior entrances
  • Garage conversions
  • Second story windows

There are also a number of development requirements specific to hillside properties.

Refer to Walnut Creek's SB 9 ordinance for more information.

The Future of SB 9 in Walnut Creek

Much like the urgency ordinance that preceded it, Walnut Creek’s permanent ordinance is quite restrictive. Although not surprising, it is disappointing that Walnut Creek is continuing to resist SB 9.

As demand and prices for homes continue to steadily rise throughout the state, every city has a responsibility to allow for more development. Hopefully Walnut Creek will loosen their restrictions in the future to make SB 9 development more feasible.

Related Posts

See if your property qualifies for SB 9.


Properties searched
map pin of possible sb 9 location

1423 Stanford Dr

  • Zoned for residential
  • In a flood zone
  • Not in a fault zone
  • Not in a high fire zone
  • Zoned for SB 9