Every city we work in, Sacramento, Elk Grove, Davis, Folsom, Woodland, and Dixon, has to honor the same state floor: no more than a 4-foot side and rear setback for a code-compliant ADU (Government Code Section 66314, subdivision (d)(7)), and no setback at all for a unit converted from an existing garage, accessory structure, or portion of the house. That's the floor, not the whole answer. The City of Sacramento's own ordinance is actually more generous than the state floor in some situations, as little as zero rear setback for a single-story ADU sitting 60 feet or more from the front property line. Woodland publishes the clearest lot coverage rule in the region: 50 percent total lot coverage, 30 percent rear yard coverage for anything over 800 square feet. Davis exempts its free pre-designed plans from lot coverage math entirely but applies a real 40/50 percent zoning cap to a custom design. Elk Grove, Folsom, and Dixon either haven't published a single ADU-specific lot coverage percentage or defer to the underlying zone's own table, and we're not going to guess at numbers we can't stand behind. Whether your specific lot clears these numbers is a zoning question, not a pricing question, so call us directly at (530) 204-8294. Once you know what fits, SafewayQuickQuote.com gives you a cost ballpark for the build itself.
The Four-Foot Number Everyone Quotes, and Why It's Only Half the Story
A homeowner in Elk Grove pulls a tape measure, marks four feet off the back fence, and calls the setback question settled. A homeowner in Sacramento does the same thing and might be leaving buildable footprint on the table, because the City of Sacramento's own municipal code lets some detached ADUs sit with zero rear setback if the unit is far enough back on the lot. Same state law. Same “4 feet” that shows up on every ADU blog in California. Two genuinely different real-world answers once you're standing on an actual parcel.
That gap is the whole subject of this post. California's Government Code sets a floor every city in this region has to honor. It does not set a ceiling on how generous a city is allowed to be, and the six cities we work across took that room to differ more than most homeowners assume.
We get some version of this question constantly: “my neighbor in Woodland says his ADU only needed a permit, mine's going through design review in Folsom, what's going on.” Usually nothing's wrong. The cities just wrote different rules on top of the same state minimum, and almost nobody has laid all six out side by side with the actual numbers.
One honest note before the comparison. Some of these figures come straight from a city's own published code or handout. A few, where we could not find a citation-grade figure, are stated as unverified and routed to the building counter instead of guessed. We'd rather tell you what we don't know than print a number that turns out wrong on your permit application.
What State Law Actually Protects
Before comparing cities, it helps to know what none of them can touch, no matter how their local ordinance reads.
Following the 2025 recodification of California's ADU statute, the ordinance-standards rules that used to live in Government Code Section 65852.2 now sit primarily in Government Code Section 66314. Section 65852.2 is superseded; a lot of ADU content still online cites it as current, which is one of the easiest ways to tell whether a source has actually been updated.
Here's what Section 66314 and its companion sections lock in as a statewide floor:
- 4-foot maximum side and rear setback. A local agency cannot require more than 4 feet from the side and rear property lines for an attached or detached ADU (Gov. Code § 66314, subd. (d)(7)).
- No setback for conversions. No setback is required at all for an ADU or JADU created within an existing living area or accessory structure, or for a replacement structure built in the same location and dimensions as what it replaces (same subdivision). That's the legal reason garage conversions almost never fight a setback battle.
- Minimum lot size can't be required. A city cannot impose a minimum lot size requirement for ADUs (Gov. Code § 66314, subd. (b)(1)).
- Lot coverage and floor area ratio can't block the protected unit. Limits on lot coverage or FAR cannot preclude an ADU of at least 800 square feet of interior livable space that maintains the 4-foot rear and side setbacks. A city can apply lot coverage math to larger ADUs, but those standards still can't unreasonably restrict the creation of an ADU generally (Gov. Code §§ 66321, subd. (b)(3); 66311).
- Default size cap without a compliant local ordinance. If a city hasn't adopted its own compliant ADU ordinance, the state default caps a new detached ADU at 1,200 square feet of interior livable space, and an attached ADU at up to 50 percent of the primary dwelling's floor area, with at least an 800-square-foot floor guaranteed regardless (Gov. Code §§ 66314, subd. (d)(4)-(5); 66321, subd. (b)(3)).
- Conversions skip unit-size math altogether. Converting an existing accessory structure or a portion of the primary residence into an ADU isn't subject to unit size requirements at all (Gov. Code § 66323, subd. (a)(1)).
- A 60-day ministerial clock. Once a complete application is in, the permitting agency has to approve or deny it within 60 days under Government Code Section 66317, amended by SB 543 effective January 1, 2026. Miss that window and the application is deemed approved by operation of law.
Every one of these is a floor, not a target. A city that writes a more permissive local rule, a smaller setback, no lot coverage percentage at all, a bigger size cap, isn't breaking any law. A city that tries to write a stricter one is the version that runs into trouble with the state.
There's also a reason none of these six cities is quietly tightening its rules on you right now. AB 130 (Chapter 22, Statutes of 2025) froze new local residential building standards statewide from October 1, 2025 through June 1, 2031, confirmed directly in the California Building Standards Commission's Information Bulletin 25-03. That's a big part of why the numbers below have held steady through 2026 and aren't likely to move under a project already in design.
Curious how your own lot measures against the state floor before you compare cities? That one's a zoning question, not a pricing question, so call us at (530) 204-8294 and we'll read your parcel's rules with you. Once you know what actually fits back there, SafewayQuickQuote.com gives you a working cost ballpark on the build itself in about two minutes.
The Six-City Comparison
| City | Side/Rear Setback | Max Detached Size | Height (Detached) | Lot Coverage Rule | Design Review Trigger |
|---|---|---|---|---|---|
| Sacramento (city) | 4 ft state floor, but the local ordinance goes lower: 0 ft for a single-story unit 60+ ft from the front property line, 3 ft if closer, 3 ft for any second-story portion (SacCC § 17.228.105(C)) | 1,200 sq ft, or 50% of the primary dwelling, whichever is greater, up to 1,200 | 16 ft by right; up to 18 ft within ½ mile of major transit | Units under 800 sq ft exempt from max lot coverage and open-space requirements (SacCC § 17.228.105) | None for a code-compliant unit — ministerial |
| Elk Grove | 4 ft under state law; city's own separate number not found in a published homeowner source | 1,200 sq ft, the region's largest ceiling | Not published for ADUs specifically; we're not printing a guess | Governed by Table 23.29-1; specific ADU percentage not published for homeowners | Attached ADUs must be architecturally compatible with the main house |
| Davis | 4 ft state standard | State default (up to 1,200 sq ft absent a stricter local rule); Davis's free pre-designed plans run 300/565/740 sq ft | 16 ft by right | General R-1 zoning caps principal-structure coverage at 40%, up to 50% combined with accessory structures — but State Exempt and Pre-Designed (Type 1) ADUs are exempt from lot coverage, FAR, and open-space rules entirely; a custom Ministerial ADU is not exempt | None for a state-exempt or pre-designed unit; a custom design needs an administrative use permit if it doesn't meet the ministerial path |
| Folsom | 4 ft | 850 sq ft (studio/1BR) or 1,000 sq ft (2+ BR) — the smallest ceiling in the region | 16 ft for the by-right lane | Not published as a flat percentage; units 801-1,000 sq ft face objective design compatibility standards instead | Any unit ≤800 sq ft, ≤16 ft, with 4-ft setbacks is a state-protected unit and skips design review entirely |
| Woodland | 4 ft | 1,200 sq ft in three tiers: ≤800 sq ft (building permit only), 801-1,000 sq ft (ADU Permit + staff design review), 1,001-1,200 sq ft (Zoning Administrator Permit) | 16 ft standard; up to 25 ft for a unit above a detached garage next to an alley; 30 ft (or the primary home's height, whichever is greater) for a two-story attached unit | 50% overall lot coverage across all structures on the parcel; 30% rear yard coverage for any ADU over 800 sq ft, both defined with worked examples in the city's own ADU handout | 801 sq ft and up triggers the ADU Permit and staff-level design review |
| Dixon | 4 ft, described in the city's own materials as the state-set maximum | 1,200 sq ft | 16 ft one-story by right; above-garage units 18-20 ft depending on configuration | Applies the base zone district's own lot coverage, FAR, open space, and front setback standards rather than one separate ADU-specific citywide percentage | Confirm with the Building Division for your parcel's zone |
A few things jump out once you see all six side by side. Woodland is the only city with a fully worked lot coverage example a homeowner can run themselves before ever calling the counter. Sacramento is the only city in this comparison where the local rule is genuinely more generous than the state's 4-foot floor, not just equal to it. Davis is the only city where whether lot coverage applies to you at all depends on which of three ADU pathways you're using. And Folsom is the outlier on size, capping out well below the 1,200-square-foot ceiling every other city in this table allows.
Need the full permit walkthrough for a specific city instead of the comparison view? We've written one for each: Sacramento, Elk Grove, Davis, Folsom, Woodland, and Dixon.
Sacramento: The One City That Beats the State Floor
Most cities in this cluster simply adopt the state's 4-foot side and rear setback and stop there. Sacramento's own municipal code, Section 17.228.105(C), goes further for certain ADUs, and it's a genuinely useful nuance almost nobody explains clearly.
If your entire ADU sits at least 60 feet back from the front property line, the first floor doesn't need any interior side or rear setback at all. Closer than 60 feet, a 3-foot minimum applies. Any second story or upper floor on a multistory ADU still needs at least 3 feet, regardless of how far back it sits. That's tighter to the property line than the 4-foot state standard everyone assumes is universal, and it can matter a lot on a narrow city lot where an extra foot on each side is the difference between fitting a detached unit and not.
Sacramento also carries the state's lot-coverage protection directly into its own code: an ADU under 800 square feet is explicitly exempt from the city's maximum lot coverage and minimum open-space requirements. Above that size, ordinary lot coverage rules for the property start to apply.
Height in Sacramento generally runs 16 feet by right, stepping up to 18 feet within a half mile of a major transit stop, which covers a meaningful share of the city given the light rail network. Detached size tops out at 1,200 square feet, or 50 percent of the primary dwelling's floor area if that's greater, capped at 1,200 either way.
Want to know exactly what your specific Sacramento parcel qualifies for before you commission a design? Call (530) 204-8294 and we'll walk through it, or start with a ballpark at SafewayQuickQuote.com.
Elk Grove: The Largest Cap, With a Gap in Public Detail
Elk Grove ties for the region's most generous size ceiling at 1,200 square feet detached, and its bigger, newer-subdivision lots are often the ones that can actually use the full allowance without a fight. The 4-foot side and rear setback applies as the state minimum.
Where Elk Grove differs from Sacramento, Davis, Folsom, and Woodland: we could not find a published, homeowner-facing ADU height figure or a specific lot coverage percentage. The city's own development standards, including numeric setback, height, lot coverage, and density figures for accessory structures, live in Table 23.29-1 of the Elk Grove Municipal Code, referenced by Chapter 23.46, but the actual numbers in that table by zoning district weren't retrievable from a public source in time for this comparison.
We're deliberately not printing a height or lot-coverage guess for Elk Grove. One real local rule we can confirm: attached ADUs have to be architecturally compatible with the main house, meaning matching style, materials, and colors, which is a heavier design lift than the flat “generally follows the primary structure's setbacks” language most of the other cities use.
If you're planning an Elk Grove project, the fastest path to a real number is Elk Grove's Building Safety, Inspections and Permits division, 8401 Laguna Palms Way, (916) 478-2235, or call us at (530) 204-8294 and we'll help you figure out exactly who to ask.
Davis: The Lot Coverage Answer Depends on Which ADU You're Building
Davis is the one city in this comparison where “does lot coverage apply to my project” doesn't have one answer, it has three, depending on which of Davis's own ADU pathways you use.
The general R-1 residential zoning rule caps a principal structure's lot coverage at 40 percent, with a combined total, primary home plus accessory structures, allowed up to 50 percent. Accessory structures and paved accessory areas, including a garage or ADU, generally can't exceed 30 percent of the required rear yard on top of that.
Here's the part that actually changes your answer. A State Exempt ADU or one of Davis's free pre-designed (Type 1) plans, the 300/565/740-square-foot catalog we've covered in our Sacramento-region pre-approved plans comparison, is exempt from lot coverage, floor area ratio, and open-space requirements entirely. A Ministerial ADU, meaning a custom design that doesn't fall into either of those two categories, is subject to the full lot coverage, FAR, and open-space math. Same city, same 4-foot setback either way, genuinely different lot coverage exposure depending on which path you take.
Setback stays at the state's 4 feet, and height runs up to 16 feet by right for a detached unit. If your lot is already tight on backyard space, a Davis pre-designed plan doesn't just save design fees, it can be the difference between clearing lot coverage math and not.
Folsom: The Smallest Ceiling, A Real State-Protected Fast Lane
Folsom stands apart on size. Folsom Municipal Code Chapter 17.105 caps a detached ADU at 850 square feet for a studio or one bedroom, or 1,000 square feet for two or more bedrooms, smaller than the 1,200-square-foot ceiling every other city in this comparison allows.
What Folsom shares with the rest of the cluster: the 4-foot side and rear setback, and a genuine state-protected fast lane. Any detached ADU of 800 square feet or less, 16 feet or under, with 4-foot side and rear setbacks, is what the state calls a “66323 unit” (Gov. Code § 66323) and cannot be denied and skips local design review entirely. Cross into 801-1,000 square feet, and Folsom's objective design standards, general compatibility with the main house in materials and style, kick in.
We could not find a published lot coverage percentage specific to Folsom ADUs. If your lot is large enough that coverage math would even be a question, Folsom's ePermit Center, 50 Natoma Street, (916) 461-6201, is the right call before finalizing a design.
Woodland: The Clearest Math in the Region
If you want a lot coverage rule you can actually run yourself before ever calling a planner, Woodland publishes it. The city's own ADU handout lays out two separate percentages, with worked examples included:
Overall lot coverage. The combined footprint of every structure on the parcel, garages, patio covers, other accessory buildings, not pools, can't exceed 50 percent of the entire lot. On a 65-by-100-foot lot, that's a 6,500-square-foot parcel, and a 50 percent cap means 3,250 square feet of total structure footprint across everything you've already built plus the new ADU.
Rear yard coverage. An ADU over 800 square feet can't cover more than 30 percent of the “backyard” area, measured from the primary home's rear wall to the rear property line. On a lot where that measurement averages 55 feet deep by 65 feet wide, roughly 3,575 square feet, the ADU's footprint tops out around 1,073 square feet.
Neither number applies to the smallest tier. An ADU that's 800 square feet or less, sits within the 4-foot setback, and stays under 16 feet in height only needs a building permit, no ADU Permit, no design review, and it's built into a straightforward tier system: 801-1,000 square feet needs an ADU Permit with staff design review, and 1,001 up to the 1,200-square-foot ceiling needs a Zoning Administrator Permit.
Height runs the standard 16 feet for a detached ADU, but Woodland allows up to 25 feet for a unit built above a detached garage that sits next to an alley, and up to 30 feet, or the height of the primary structure, whichever is greater, for a two-story attached ADU. Both of those exceed what every other city in this comparison allows for height.
Dixon: No Separate ADU Percentage, Just the Underlying Zone's Own Rule
Dixon takes a different approach than Woodland's clean, ADU-specific 50/30 split. Dixon applies the base zoning district's existing lot coverage, floor area ratio, open space, front setback, and minimum lot size standards to ADUs directly, rather than writing one separate percentage that applies citywide regardless of zone.
That's not a gap in the ordinance, it's a design choice, and it's a legitimate one. It does mean the actual coverage percentage you're working with in Dixon depends on which zoning district your parcel sits in, something Dixon's own Building Division can confirm faster than any published guide can generalize. The 4-foot setback and 1,200-square-foot detached cap both apply across the board regardless of zone, and Dixon's by-right lane mirrors the rest of the cluster: a detached unit 16 feet or under with 4-foot setbacks skips design review. Above-garage units can run 18-20 feet depending on the specific lot configuration.
Dixon's Building Division sits at 600 East A Street. If you're not sure which zoning district your Dixon parcel falls into, that's the fastest way to get a real number rather than a regional average.
Why Lot Coverage Rarely Kills a Sacramento-Region ADU
Here's the thing almost nobody says plainly: on most lots in this region, lot coverage never actually becomes the limiting factor. The size cap does that job first.
State law already guarantees that a lot coverage rule can't block an ADU up to 800 square feet with the standard 4-foot setbacks. Above that size, every city in this comparison also caps the unit itself, at 1,200 square feet in five of the six cities, or 850-1,000 square feet in Folsom. A homeowner with a typical suburban lot in Elk Grove or Woodland usually hits the size ceiling, or simply decides a smaller unit makes more financial sense, well before a lot coverage percentage would have stopped them anyway.
Where lot coverage actually bites is the property that's already built out: a big primary house, an existing pool house or workshop, a large detached garage, all eating into that 50 percent overall figure Woodland spells out. If your lot already carries a lot of structure, that's exactly the parcel where a coverage rule, not the size cap, becomes the real design constraint, and it's worth running the numbers before you fall in love with a floor plan.
If Your Lot Doesn't Fit the Numbers
A few paths usually still work even on a genuinely tight lot:
- Garage conversion. No added setback requirement under state law, since it's built within an existing structure. This is often the cleanest option on a lot where a new detached structure simply won't clear the numbers.
- Drop under 800 square feet. In Sacramento and Woodland specifically, staying under that threshold exempts you from the city's lot coverage add-on rules entirely, on top of the state protection that already applies everywhere.
- Go attached instead of detached. Attached ADUs generally follow the primary home's existing setback lines rather than the ADU's own 4-foot minimum, which can solve a narrow side yard that a detached structure can't.
- A Davis pre-designed plan, if you're building in Davis specifically, sidesteps the city's lot coverage math altogether, something a custom design in the same city doesn't get.
This is exactly the kind of parcel-specific question that's worth a real conversation before you pay for a design. Call (530) 204-8294 and we'll go through your lot together.
What This Costs, Region-Wide
Setback and lot coverage rules decide what you're allowed to build. They don't set the price. Cost figures below are the same baseline we use consistently across our Sacramento-region ADU guides:
| ADU Type | Construction Cost | All-In (permits, design, utility work) |
|---|---|---|
| Garage conversion | $60,000-$140,000 | $80,000-$160,000 |
| Attached ADU | — | $145,000-$260,000 |
| Detached ADU (standard) | — | $175,000-$340,000 |
Folsom's smaller size ceiling, 850-1,000 square feet against the 1,200-square-foot cap most other cities allow, means a Folsom detached ADU commonly lands toward the lower-to-middle end of that range simply because the finished unit is physically smaller. A Sacramento or Elk Grove project built out to the full 1,200-square-foot allowance runs closer to the top.
Want a number specific to your actual lot, not a regional range? Try the Safeway ADU cost calculator or run a free estimate at SafewayQuickQuote.com, about two minutes, no site visit required for the initial ballpark.
Two Different Questions, Two Different Answers
It's worth separating these clearly, because they get conflated constantly. “Does my lot qualify for this setback or lot coverage allowance” is a zoning compliance question. Nobody, including us, can answer it accurately without looking at your actual parcel, your zoning district, and in some cities your specific lot dimensions. That's a phone conversation, not a form. Call (530) 204-8294 and we'll help you figure out where your lot actually lands against these numbers.
“What will it cost to build once I know what fits” is a different, much more answerable question, and that's exactly what SafewayQuickQuote.com is built for: a working cost range in about two minutes, no site visit required to get started.
Frequently Asked Questions
What is the minimum ADU setback required across the Sacramento region?
State law, Government Code Section 66314, subdivision (d)(7), caps what any city can require at four feet from the side and rear property lines for an attached or detached ADU. All six cities in this comparison use that as their baseline. A city can require less, and Sacramento's own ordinance does in some situations, but none can legally require more.
Can a city require more than a 4-foot setback for a detached ADU?
No, not for a code-compliant unit that meets the state's protected size and design standards. Section 66314 sets four feet as the ceiling a local agency can impose on the side and rear yards. Cities can go more permissive; they can't go stricter.
Does an ADU built inside an existing garage need any setback at all?
Generally no. Under Government Code Section 66314, subdivision (d)(7), no setback is required for an ADU or JADU created within an existing living area or accessory structure, or for a replacement structure built in the same location and dimensions as what it replaces. That's why garage conversions rarely run into a setback fight.
Can lot coverage rules stop a city from approving my ADU?
Not for the state-protected size. Lot coverage or floor area ratio limits cannot preclude an ADU of at least 800 square feet that maintains the four-foot rear and side setbacks. Cities can apply lot coverage math to larger units, and several in this region do, but those rules can't be used to unreasonably block ADU creation generally.
Which Sacramento-region city has published the most detail on lot coverage rules?
Woodland, by a wide margin: 50 percent total lot coverage across the parcel, 30 percent rear yard coverage for any ADU over 800 square feet, with worked examples in the city's own handout. Sacramento and Davis both have real, citable rules structured differently. Elk Grove, Folsom, and Dixon either haven't published a single ADU-specific percentage or apply the base zone's own standard instead.
Why doesn't every city publish the same lot coverage percentage?
Because state law only requires a city to not block the protected 800-square-foot ADU. It doesn't require a single, simple, ADU-specific percentage in a public handout. Some cities wrote one anyway. Others apply whatever coverage standard already exists for the parcel's underlying zoning district. Both are legal; only one is easy to research from home.
Can a city change its setback or lot coverage rule while my permit is pending?
Practically, no city in this cluster can add a new, stricter local residential building standard right now at all. AB 130 (Chapter 22, Statutes of 2025) froze new local residential building standards statewide from October 1, 2025 through June 1, 2031, per the California Building Standards Commission's Information Bulletin 25-03. The numbers in this comparison aren't likely to tighten under a project already in design.
What if my lot doesn't fit any of these setback or lot coverage numbers?
A garage conversion carries no added setback requirement since it's built within an existing structure. Staying under 800 square feet often exempts the unit from a city's local lot coverage add-on rules. An attached ADU generally follows the primary home's existing setback lines instead of the ADU's own four-foot minimum. This is exactly the kind of question worth a phone call before you pay for a design.
Related Guides
- Sacramento ADU Guide: Permits, Costs & Rental Income (2026)
- Elk Grove ADU Guide: Permits, Costs & Pre-Approved Plans (2026)
- Davis ADU Guide: Permits & Free Pre-Approved Plans (2026)
- Folsom ADU Guide: Permits, Costs & Local Rules (2026)
- Woodland ADU Guide: Permits, Costs & Local Rules (2026)
- Dixon ADU Guide: Permits, Costs & Local Rules (2026)
- Pre-Approved ADU Plans in the Sacramento Region: A 2026 City-by-City Comparison
- ADU vs. Second-Story Addition in Sacramento and Davis (2026)
Get a Straight Answer for Your Lot
We're a licensed California general contractor (CA Lic. #1066117) with 20+ years of construction experience across California and a 5.0-star Google rating. We have a project manager on the ground in the Davis and Sacramento region, and we work across all six cities in this comparison. Setback and lot coverage rules are a compliance question first, a design question second, and a cost question last.
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