Everything homeowners need to know about building an accessory dwelling unit in Fresno - size limits, setbacks, permits, and how the city's free pre-approved plans and streamlined review have driven real, documented growth in ADU applications.
Last verified: August 2026
8/10 · ADU-friendly
1,200 sq ft
Max ADU size
16 ft
Max height
Not required
Owner-occupancy
By-right
Permit type
This page summarizes Fresno Municipal Code Section 15-2754 (Second/Accessory Dwelling Units), part of the city's unified Development Code, layered on top of California's statewide ADU law (Gov. Code Sec 65852.2 and related sections), for general reference - it is not legal advice. Regulations change; always confirm current requirements with the City of Fresno Planning and Development Department before designing or applying for permits. See sources below.
Zoning & size requirements
What you're allowed to build
ADU type
Max size
Max height
Notes
Detached (new construction)
Up to 1,200 sq ft
16 ft
Must match or complement the primary residence's exterior materials and finishes
Attached (addition to primary home)
50% of the primary dwelling's floor area, up to the citywide 1,200 sq ft cap
Same as primary structure
Converted (garage, interior)
Sized to the existing structure's footprint
Same as existing structure
Exempt from new-construction setback requirements
Junior ADU
Up to 500 sq ft, built within the primary home's existing walls
Same as primary structure
Owner-occupancy applies only if the JADU shares sanitation facilities with the main house
Allowed zoning districts
Allowed citywide on residentially zoned lots. Fresno runs one of the more developed ADU programs among Central Valley cities: 5 free pre-approved floor plans (from a 340 sq ft studio up to a 1,015 sq ft 3-bedroom), each offered in 3 design styles with solar panels included, and pre-approved and custom ADU plans no longer require a separate Zone Clearance - applications go straight to a building permit.
Additional standards
Setbacks, parking & other rules
Setbacks
Minimum 5 ft side and rear setbacks for new-construction ADUs; conversions of legally established structures are exempt
Parking
Generally 1 space per bedroom, waived within 1/2 mile of public transit or for many garage conversions; never required for a JADU
Units per lot
At least 1 ADU (attached or detached) plus 1 JADU on a qualifying single-family lot, the floor set by state law
Owner-occupancy
Not required for a standard ADU; a JADU only requires it when the unit shares sanitation facilities with the primary home
Building code
Must meet current California Building, Residential, Energy, Plumbing, Mechanical, and Electrical Code standards
Fire sprinklers
May be required depending on the primary residence's existing sprinkler status, proximity to property lines, or fire department access - confirm early for your specific lot
Impact fees
Waived for ADUs at or under 750 sq ft; charged proportionally to the primary dwelling's fee above that
Ordinance history
How Fresno's ADU rules got here
2015Unified Development Code adopted. Fresno folds its accessory dwelling unit standards into a single citywide development code.
2017Statewide ADU law takes effect. California's Gov. Code Section 65852.2 begins requiring ministerial, by-right approval of qualifying ADUs.
2022Pre-approved ADU plan program launches. The city's shelf-ready blueprint library opens, though uptake starts small: about 8 applicants use it in the program's first year.
2023Applications surge. ADU applications jump to roughly 56 for the year, a roughly 600% increase, as the pre-approved plan program gains traction alongside the statewide law changes of the preceding years.
2024Program expands and process shortens. The pre-approved plan library grows to 5 designs across 3 elevation styles with solar included, and the city eliminates the separate Zone Clearance step so applications move directly to a building permit. Statewide, AB 976 eliminates owner-occupancy requirements and SB 1211 allows multifamily properties to add multiple detached ADUs.
Of the three Central Valley cities on this site, Fresno has the most documented momentum: city planning staff have publicly credited the streamlined process for the growth, and local homeowners profiled in regional reporting describe using ADUs for both rental income and housing family members on larger Central Valley lots. It's still a modest program by the standards of the biggest California metros, but the trend line is real and locally sourced, not just a byproduct of state law existing on paper.
Permit process
How Fresno ADU permitting works
1
Pre-application check
Call the ADU Hotline or check with Planning and Development to confirm zoning eligibility and browse the pre-approved plan library.
2
Choose a pre-approved plan or prepare a custom plan set
A pre-approved plan needs only a site-specific site plan; a custom design needs a full plan set addressing setbacks, lot coverage, and unit height.
3
Submit directly for a building permit
Zone Clearance is no longer a separate step - applications go straight to the Building and Safety Division.
4
Plan check
The city reviews for zoning and building code compliance, including whether fire sprinklers apply to your specific lot; state law requires a completeness determination within 15 business days.
5
Permit issuance
Complete applications must be decided within 60 days under state law, or the application is deemed approved.
6
Construction & inspections
Schedule the standard framing, plumbing, electrical, and final inspections as work proceeds toward a certificate of occupancy.
Fees and timelines are approximate and change periodically - confirm current figures with the ADU Hotline at (559) 621-8077 before you budget or apply.
Budgeting
What it costs to build an ADU in Fresno
Garage conversion
Roughly $60,000-$150,000, the least expensive path since the shell already exists
Interior or addition conversion
Roughly $90,000-$180,000; true basement conversions are uncommon in Central Valley home construction, so this more often means an attached addition or converted interior space
New detached ADU
Roughly $130,000-$280,000+ for a code-compliant, fully finished freestanding unit; local reporting on Fresno-area builds has cited figures from about $60,000 for a small prefabricated unit up to $200,000+ for a larger ground-up build
Pre-approved plan savings
Regional reporting on Fresno projects has put the design-cost savings from using a pre-approved plan at roughly $2,000-$4,000 versus a fully custom design
Impact fees
Waived for ADUs at or under 750 sq ft; larger units are charged proportionally to the primary home's fee
These are general ranges from local contractor estimates and regional reporting, not quotes - actual cost depends heavily on lot conditions, finishes, and whether you use a pre-approved plan versus a custom design. One Fresno-area homeowner told local media he spent roughly $15,000 in fees alone before construction even began, a reminder to budget for soft costs, not just materials and labor.
Before you apply
Tips for a smooth approval
Start with the pre-approved plan library. Five designs across three elevation styles cover a wide range of needs, and skipping custom design can save real money and time.
Keep your ADU at or under 750 sq ft if cost matters most. It clears the statewide impact-fee waiver threshold entirely.
Ask about fire sprinklers early. Whether they're required depends on your existing home and lot conditions, and it can meaningfully change your budget if you don't plan for it upfront.
Budget for soft costs, not just construction. Fees, plan review, and utility connections add up before a shovel hits the ground - ask for an itemized estimate.
Decide on rental plans before you build. Short-term and long-term rentals carry different permit and tax obligations, so it's easier to plan the layout and paperwork together from the start.
FAQ
Common questions
Do I need to live on the property to build an ADU in Fresno?
No, not for a standard ADU. Under statewide AB 976, cities can no longer require owner-occupancy for a standard ADU. A JADU only carries an owner-occupancy requirement if it shares bathroom or kitchen sanitation facilities with the primary home.
How many ADUs can I build on one lot?
State law entitles a qualifying single-family lot to at least one ADU (attached or detached) plus one JADU. Multifamily properties can add more under SB 1211 - confirm specifics with the city.
Do I need extra parking for an ADU?
Generally the city can require one space per bedroom, but that's waived within 1/2 mile of public transit and for many garage conversions, and a JADU can never be required to add parking.
How long does the permit process take?
State law requires a completeness determination within 15 business days and a decision within 60 days of a complete application, or the application is deemed approved. Using a pre-approved plan tends to move faster in practice since the design itself doesn't need review.
What's the maximum size for a detached ADU?
Up to 1,200 sq ft, with a 16 ft height limit and a 5 ft minimum side/rear setback for new construction.
How much does an ADU cost to build in Fresno?
Garage conversions and small prefabricated units tend to start around $60,000, mid-range interior or addition conversions run roughly $90,000-$180,000, and larger new detached units can run $200,000 or more, based on local contractor estimates and regional reporting.
What are Fresno's pre-approved ADU plans?
A library of 5 free floor plans, ranging from a 340 sq ft studio to a 1,015 sq ft three-bedroom unit, each available in Craftsman, Contemporary, or Gable styles with solar panels included. Choosing one instead of a custom design has been estimated to save roughly $2,000-$4,000 in design costs and can speed up review.
Do I need a permit to rent my ADU short-term on Airbnb?
Yes. Fresno requires a Short Term Rental permit (a combined $50 application and permit fee) before you advertise or rent, plus collection of a 12% transient occupancy tax and an additional 2% tourism business improvement district fee. The permit holder must be the property owner and renews annually.
Are impact fees really waived for small ADUs?
Yes. Under state law, ADUs at or under 750 sq ft are exempt from development impact fees, and larger units are charged proportionally to the primary home's fee.
