Two neighbors on the same Sacramento street both add a backyard cottage. One is told to hold a full front-yard setback and match the zone's side yards. The other builds with no setback at all on three sides. Neither was given special treatment. The difference is where on the lot the cottage sits, and which of the city's two rulebooks each owner applied under.
Sacramento offers two separate development options for accessory dwelling units, and the code is blunt about mixing them: the two options may not be combined (§ 17.228.105(A)). Option B is the city's own local rulebook. Option C follows the state's ministerial path instead. You choose one at application, and that choice governs your setbacks, your rental rights and your approval route.
An accessory dwelling unit — ADU — is a second, self-contained home on a lot that already has one.
The 60-foot line: Sacramento's signature rule
Most cities publish one setback for backyard units. Sacramento publishes two, and the boundary between them is a measurement almost nobody thinks to take: the distance from the front property line to the nearest corner of the proposed unit (§ 17.228.105(B)(2)(c)(iii)).
| Where the unit sits | Front | Interior side and rear |
|---|---|---|
| Within 60 feet of the front property line | Zone's front-yard setback | Zone's requirement or 3 feet, whichever is less |
| Beyond 60 feet, single story or first floor | None required | None required |
| Beyond 60 feet, second floor and above | Not applicable | Zone's requirement or 3 feet, whichever is less |
Street side-yard setbacks apply in every case. And converting an existing structure carries no setback requirement — nor does rebuilding one in the same location to the same dimensions (§ 17.228.105(B)(2)(c)(iii)). That single sentence is why so many Sacramento projects start with an existing detached garage.
Measure before you design. Thirty inches of difference in where the cottage lands can be the difference between a zone setback and none.
The levee rule
Sacramento sits between two rivers, and its ordinance carries a clause most cities have no use for: an accessory dwelling unit may not project into the required setback from the landside toe of a levee (§ 17.228.105(B)(2)(c)(iii)). If your rear property line runs toward a levee, that setback is a hard edge no other provision relaxes.
When the back yard genuinely will not fit one
Narrow and oddly shaped lots get a relief valve. Sacramento permits one unit of 800 square feet or less to be built within the front-yard setback, but only where the rear and side yards cannot accommodate either a two-story detached unit of at least 800 square feet or an attached unit of at least 800 square feet (§ 17.228.105(B)(2)(c)(iii)(4)). Both conditions must fail before the front yard opens up. It is a last resort written into the code, not a design preference.
Coverage, and the balcony height rule
Your zone's height, lot coverage and open-space standards apply as the general rule — with a carve-out: a unit occupying less than 800 square feet of lot coverage is exempt from maximum lot coverage and minimum open-space requirements (§ 17.228.105(B)(2)(c)(ii)).
Then there is the standard that catches designs late, after elevations are drawn. No part of a balcony, deck or open-stair landing within 10 feet of a rear or side lot line may sit higher than three feet above the ground — unless that lot line abuts a nonresidential use, an alley, or a public or approved private street (§ 17.228.105(B)(2)(c)(v)). A second-floor deck facing a neighbor's yard is the exact thing this rule removes.
Two more local standards travel with the unit: it must conform to the objective design standards applicable to the lot, and if the property is in a historic district or landmark-designated, to the city council's separately adopted objective standards for those properties (§ 17.228.105(B)(2)(c)).
The short-term rental difference nobody mentions
This is the most consequential practical distinction between Sacramento's two options, and it runs opposite to what people assume.
A unit approved under the city's local option may be rented for a term of less than 30 days, in accordance with the city's separate short-term rental section (§ 17.228.105(B)(1)(c)). A unit created under the state's ministerial path may not — state law requires the local agency to insist on rentals longer than 30 days (Gov. Code § 66323).
If a short-term rental is part of your plan, that fact alone may decide which option you apply under.
Junior units carry an owner-occupancy string
A junior accessory dwelling unit is built within the walls of a single-unit dwelling, which may include an attached garage, and needs an entrance separate from the main door. Unlike a standard ADU, it comes with an owner-occupancy requirement — the property owner must live on site unless the property is owned by a government agency, land trust or housing organization (§ 17.228.105(B)(3)).
That requirement is not a promise; it is recorded. A deed restriction must go on file before final building permit inspection, stating that the junior unit may not be sold separately, that the restriction binds future purchasers, and that the unit's size and attributes may not deviate from the permit (§ 17.228.105(B)(3)).
A shed with a sink is not an ADU
Sacramento's general accessory-structure rules draw the line plainly:
An accessory structure shall not be used as a dwelling or separate living quarters (§ 17.624.030).
A detached accessory structure may hold laundry and sanitary facilities — a water heater, sink, toilet or shower — plus heating, but no kitchen (§ 17.624.030). The kitchen is what turns a workshop into a dwelling unit, legally and practically.
Two protections that apply either way
Whichever option you use, state law removes two obstacles the city cannot re-impose. A permit cannot be denied because of nonconforming zoning conditions, building code violations or unpermitted structures that do not threaten health and safety and are not affected by the work (Gov. Code § 66322). And fire sprinklers cannot be required in the unit if they are not required for the main house (Gov. Code § 66323).
Before you draw
Take three measurements first: the distance from your front property line to where the unit would sit, the distance to any levee toe, and your zone's base setbacks. Then decide which option you are applying under — knowing that the choice, not the drawings, determines whether you can rent it by the week. State guidance encourages cities to write ordinances that go beyond the minimum, and Sacramento's local option is one (2025 California ADU Handbook). Our Sacramento ADU guide and Sacramento code overview carry the permitting detail.
Sources
- Sacramento City Code § 17.228.105 — Accessory dwelling units and junior accessory dwelling units
- Sacramento City Code § 17.624.030 — Residential accessory structure general regulations
- Government Code § 66322 — Parking and nonconforming conditions
- Government Code § 66323 — Ministerial approval path
- 2025 California ADU Handbook — Local ADU ordinances and local agencies
