







A free site visit, a check of what your lot allows and a written, line-item price.
Get your free estimateTrusted ADU Builders for Fresno Homeowners
Building an accessory dwelling unit in Fresno means adding square footage that pays you back every month, whether it’s rental income, a place for aging parents, or room for a growing family. Benson ADU Builders - Fresno has been part of the Relay Home Co. family since 2006, and we’ve spent those years getting very specific about what Fresno homeowners actually need: a written price before work starts, a plan that survives the permit desk, and a structure built to handle Central Valley summers that hit 105 degrees. No verbal estimates that drift. No waiting weeks for a callback. Call (559) 206-2363 and you’ll get a live person who can walk you through your options, from a compact JADU inside your existing home to a detached two-bedroom in the backyard.
Key Takeaways
- A site-built ADU in Fresno typically runs $180,000 to $320,000 depending on size, finishes, and site conditions.
- Prefab ADUs from brands like Abodu, Cover, and Dvele usually land between $150,000 and $280,000 including site work.
- Every Benson ADU Builders project includes a written price, a 365-Day Done Right Promise, and a written guarantee on the work.
- Fresno’s ADU ordinance allows detached units up to 1,200 square feet and JADUs up to 500 square feet.
- We handle plans, permitting, site prep, foundation, construction, and final inspection under one contract.
ADU Construction
ADU Construction is the full process of taking a backyard, side yard, or underused garage and turning it into a legal, livable second home on your Fresno property. It’s the umbrella term for everything from demolition and foundation work to framing, electrical, plumbing, drywall, and finish carpentry. When you’re dealing with Fresno’s specific soil conditions, hard water, and summer heat, you need a builder who doesn’t get surprised by a cracked foundation line or an undersized HVAC rough-in. Benson ADU Fresno manages the entire job with a single point of contact and a written scope of work. Expect a site-built detached ADU in Fresno to run $180,000 to $320,000, with prefab options starting around $150,000.
Site-Built vs. Prefab Panels
Site-built ADUs are framed on your property, which gives you total control over dimensions, rooflines, and finishes. Prefab panel systems, like those from Plant Prefab and Dvele, arrive as factory-built wall sections and roof cassettes that go up in days instead of months. Both paths work in Fresno; the choice comes down to how much design flexibility you want versus how fast you need the unit occupied.
Permit-Ready Site Work
Before any walls go up, we handle grading, drainage, and utility trenching to Fresno’s current code. That means pulling the right permits, scheduling inspections, and making sure your ADU doesn’t create drainage problems for your existing home. The goal is a foundation that’s flat, dry, and ready for whatever structure sits on it.
Detached ADU

A Detached ADU is a standalone dwelling unit built in your backyard, fully separated from your main house by at least six feet on every side. Fresno homeowners choose detached ADUs for maximum privacy, whether that’s a rental tenant, a college-age kid, or an in-law who wants their own front door. These units are the most popular ADU type in Fresno and they’re also the most involved, since they need their own foundation, utility connections, and address. Benson ADU Fresno builds detached units from 400 to 1,200 square feet under Fresno’s current ADU ordinance. Budget $180,000 to $320,000 for a site-built detached ADU, or explore prefab units from Abodu, Cover, and Dvele that typically range from $150,000 to $280,000.
Fresno Setback Rules, Explained
A setback is the required distance between your ADU and your property line. In Fresno, detached ADUs need a minimum four-foot side and rear setback. That detail shapes how big your unit can be, so we verify your lot dimensions and zoning before we recommend a floor plan.
Utility Connections That Actually Work
A detached ADU needs its own electrical panel, water service, and sewer or septic connection. We plan the trenching route early so you’re not tearing up a newly poured patio later. Our written price includes these connections, not just the visible structure.
JADU
A JADU, short for Junior Accessory Dwelling Unit, is a small living unit created from existing space inside your main house, up to 500 square feet, with its own entrance, kitchenette, and private bathroom. It’s the fastest and least expensive way to add a rental unit to your Fresno home, because you’re converting a garage, bonus room, or finished basement rather than building from the ground up. JADUs are legal under California state law and Fresno’s local ordinance, and they often skip the impact fees that apply to larger detached units. Benson ADU Fresno handles the conversion, plumbing, electrical, and fire-safety details. A garage conversion JADU in Fresno typically runs $80,000 to $150,000, while an interior room conversion inside your existing footprint often lands between $50,000 and $100,000.
Garage Conversion vs. Interior Conversion
Converting a garage gives you a fully separate entrance and more privacy for a tenant. Converting an interior room, like a spare bedroom or den, moves faster because the shell already exists. Both routes require updating the space to meet current energy and safety codes, which we include in the written price.
Fire Separation and Code Compliance
Because a JADU shares walls with your main home, Fresno code requires upgraded drywall, self-closing doors, and linked smoke and carbon monoxide alarms between the two units. We pull the permits and schedule the inspections so you’re not guessing at the fire marshal’s final walkthrough. This work is not DIY territory; a botched fire separation can fail inspection and delay your certificate of occupancy.
ADU Plans

ADU Plans are the architectural drawings, structural calculations, and site documents that Fresno’s Building and Safety department reviews before you can legally build an accessory dwelling unit. Without stamped plans, you can’t get a permit. Without a permit, your ADU isn’t legal, your insurance may not cover it, and you can’t rent it out. Most Fresno homeowners need plans drafted by a designer or architect who understands California’s ADU laws, including the state’s 60-day approval requirement for complete applications. Benson ADU Fresno includes plan development as part of every project, or we’ll review plans you’ve already purchased. Plan sets for a standard Fresno ADU typically cost $4,000 to $10,000 when purchased separately, but they’re included in our full build contracts.
What a Complete Plan Set Includes
You need floor plans, elevations, a site plan showing setbacks and utility locations, structural details, and Title 24 energy calculations. California’s Title 24 energy code is strict about insulation, windows, and HVAC sizing for ADUs. A complete set also specifies exactly which materials and finishes get used, which is what lets us give you a written price with no change orders later.
Working With Existing Plans
If you already bought plans online or hired a designer before finding us, we’ll review them for Fresno code compliance before you spend another dollar. We regularly find missing structural details or outdated Title 24 calcs that would bounce the permit application. We’ll tell you what’s fixable and what needs a redraw, in plain English, before you commit.
ADU Contractor
An ADU Contractor is the licensed, insured professional who manages your entire accessory dwelling unit build from permit to move-in, and in Fresno that person either makes or breaks your project. A good contractor coordinates the designer, the city, the subs, and the inspections. A bad one disappears after deposit day. More than one Fresno homeowner has chased a contractor for months over a half-finished ADU shell. Benson ADU Fresno operates under The Relay Visibility Guarantee, which means a written price before work starts, real-time project tracking, and a 365-Day Done Right Promise on every single build. Full ADU construction management in Fresno runs $180,000 to $320,000 depending on unit size and scope.
Vetting a Contractor in Fresno
Check the California Contractors State License Board before you sign anything. Ask for a written scope of work, not a verbal estimate. Ask how change orders are handled and what happens if the project runs long. If a contractor won’t put their price and their timeline in writing, keep looking. We’re happy to put both in front of you on the first call.
Why Our Technicians Look Different
Every Benson ADU Fresno technician is background-checked and arrives in uniform, so you always know exactly who’s on your property. That’s a small thing until a stranger is walking through your backyard gate. Our written price means the crew’s scope is locked before day one; nobody’s showing up to charge you extra for something “they found” mid-project.
ADU Design

ADU Design is the process of shaping your accessory dwelling unit to fit your lot, your budget, and how you’ll actually use the space, and it’s the fastest way to waste money or save it, depending on how deliberate you are. In Fresno, design decisions like window placement, roof orientation, and insulation affect both your cooling bill and your tenant’s comfort in August. A well-designed ADU also rents faster and appraises higher. Benson ADU Fresno offers curated design packages built around prefab brands like Abodu, Cover, and Dvele, plus fully custom site-built options for irregular lots. Design-only engagements, where we produce plans without construction, typically cost $5,000 to $12,000. Full design-build packages include design at no separate line item.
Designing for Central Valley Heat
A Fresno ADU should be oriented to minimize west-facing glass and maximize morning light. Light-colored cladding, reflective roofing, and a properly sized mini-split system matter more here than in coastal California. These are the kinds of decisions we bake into every plan, because retrofitting them later costs thousands.
Matching Your Main House
Fresno zoning doesn’t require your ADU to match your main house, but a unit that shares similar rooflines, colors, and trim details looks like it belongs there. We’ll design something that fits your lot without pretending to be a miniature version of your home. The goal is a backyard that feels intentional, not an afterthought.
Backyard ADU
A Backyard ADU is simply a detached accessory dwelling unit placed in your rear yard, and it’s what most Fresno homeowners picture when they hear “granny flat” or “casita.” It’s the highest-value ADU type because it adds entirely new square footage without touching your existing home, which means your daily life doesn’t get disrupted during construction. You keep your kitchen, your parking, and your routine. Benson ADU Fresno builds backyard units that work with Fresno’s lot shapes, which range from deep and narrow in Tower District to wide and shallow in newer subdivisions along the 168 corridor, and we’ve applied that same expertise as Clovis ADU Builders for nearby homeowners. Expect $180,000 to $320,000 for a site-built backyard ADU, or $150,000 to $280,000 for a prefab model from Abodu, Dvele, or Cover.
Maximizing Your Usable Yard
Most Fresno backyards have space for a 400 to 800 square foot ADU without losing the whole lawn. We help you decide where the unit sits, how the pathway to the front of the house works, and where the private outdoor space for the tenant begins. The layout matters as much as the building.
Foundation Options for Fresno Soil
Fresno’s expansive clay soil expands and contracts with moisture swings, which can crack a poorly detailed slab. We spec footings and slabs designed for the specific soil on your lot, not a generic detail pulled from a template. That’s the kind of thing that shows up five years later, and it’s exactly what our 365-Day Done Right Promise covers.
Brands We Service
Benson ADU Fresno is authorized to build with Abodu, one of the most established prefab ADU companies in California. Their units are known for high-quality finishes and a design-forward aesthetic that fits modern California neighborhoods. We handle the site work, foundation, and utility connections that Abodu’s factory-built modules sit on, plus the final interior finish details.
We also build with Cover, a precision-engineered prefab brand that ships steel-framed wall and roof panels cut to the millimeter in a Los Angeles factory. Cover units go up fast and the fit-and-finish is exceptional. For homeowners who want a higher-end site-built or panelized option, Dvele builds homes with an emphasis on energy performance and healthy materials. Whether you want an Abodu studio, a Cover one-bedroom, a Dvele two-bedroom, or a fully custom site-built ADU with James Hardie cladding, we can source it, permit it, and build it. If you already have plans for another brand, we’ll happily review them too.
Signs You Need a Pro Right Now
- Your garage conversion stalled at the permit stage. Fresno’s Building and Safety department bounces incomplete ADU applications all the time. If your plans came back with corrections you don’t understand, call us before you burn another month. We can rework the plans and resubmit quickly.
- A previous contractor walked off mid-project. A partially framed ADU shell exposed to Fresno weather is active damage in progress. The longer framing sits unsealed, the more rot and warping you’re paying for later. We can assess what’s salvageable and what needs to come down.
- Your main house can’t handle the electrical load. A detached ADU with a mini-split, water heater, and kitchen appliances often needs a service upgrade from 100 to 200 amps. If a contractor quotes you an ADU without checking your panel, that price is fiction. We check the panel before we quote.
- You’re not sure if your lot can even fit an ADU. Setback requirements, lot coverage limits, and utility easements vary block by block in Fresno. A quick consult can tell you what’s buildable before you spend money on plans. The wrong lot assumption can waste $5,000 in design fees.
- You want to rent the unit but haven’t planned for tenant access. A rental ADU needs a clear path to the front door, separate utility metering, and privacy screening from your own outdoor space. Retrofitting access after the unit is built is expensive and awkward. We plan tenant circulation on day one.
Our Process, Step by Step
Here’s how we build ADUs in Fresno, from first call to final inspection, without the mystery.
1. Initial Call and Site Review
Call (559) 206-2363 and you’ll reach a live person, not a voicemail tree. We’ll ask about your lot, your goals, and your rough budget. Then we schedule a site visit where we walk the property, check the panel, measure setbacks, and photograph the site. After the visit, you get a written proposal with a price.
2. Design and Plan Development
We design your ADU to your lot and budget, pulling from our prefab brand catalog or drafting custom plans. Title 24 energy calculations, structural details, and site plans get included. You review and approve the plans before anything goes to the city.
3. Permitting and Approval
We submit the full plan set to Fresno’s Building and Safety department and manage the review process. California requires cities to act on complete ADU applications within 60 days. We track the application, answer plan check comments, and get your permit issued.
4. Construction
Site prep, foundation, utility connections, framing or panel installation, MEP rough-in, insulation, drywall, finishes. You get real-time project tracking and before-and-after photos at each phase. Our background-checked, uniformed crews keep the site clean and secure.
5. Final Inspection and Walkthrough
We schedule the final inspection, walk the unit with you, and hand over the keys along with your written guarantee. If anything isn’t right within 365 days, we make it right. Your digital invoice is payable by link, and your file stays accessible.
How Much Do ADU Builders Cost in Fresno?
A typical detached, site-built ADU in Fresno runs $180,000 to $320,000 depending on square footage, site conditions, and finish level. Prefab ADUs from Abodu, Cover, or Dvele typically land between $150,000 and $280,000 including site work, foundation, and utility connections. A JADU conversion inside your existing home is the most budget-friendly path at $50,000 to $150,000 depending on whether you’re converting a garage or an interior room. Plan-only engagements, where you just need stamped drawings to permit the job yourself, run $4,000 to $12,000.
What moves the price? Lot access, trenching distance to your sewer and electrical panel, soil conditions, finish selections, and whether your existing panel needs a service upgrade. Prefab units reduce framing labor and weather delays, which is why they can come in lower than site-built. The best way to avoid overpaying is a written scope of work that lists every line item before you sign. That’s what we give you. Your free estimate includes a site visit, panel check, setback verification, and a written proposal with a fixed price. Call (559) 206-2363 to schedule yours.
Our Service Area Near Fresno
Benson ADU Fresno builds ADUs across Fresno County and the surrounding Central Valley. We regularly serve homeowners in Fresno, plus Sanger, Kerman, Clovis, Madera, Selma, Reedley, Kingsburg, Parlier, and the smaller communities in between. If you’re within roughly 45 minutes of Fresno, we can quote your project. Our service area also extends toward Hanford, Los Banos, and Coalinga on a project-by-project basis. Call us and we’ll tell you straight whether we can get to your lot.
Serving Fresno, CA - Our Local Coverage Area
We’re based in the Fresno area and know this community well. Use the map below to see our service coverage - if you’re nearby, we can almost certainly help.
Frequently Asked Questions About ADU Builders in Fresno
ADU builders handle every phase of adding an accessory dwelling unit: site assessment, design, permitting, foundation, utility connections, framing, and finish work. In Fresno, a full-service ADU builder also manages the city’s review process and schedules all inspections. At Benson ADU Fresno, you get a single point of contact and a written price before any work begins.
A JADU conversion typically takes 3 to 6 months from permit to move-in. A detached, site-built ADU usually takes 6 to 12 months depending on size and site conditions. Prefab units from Abodu, Cover, or Dvele can trim 2 to 4 months off the construction timeline. Fresno’s permit review is legally capped at 60 days for complete applications, but plan corrections and inspection scheduling add time.
A detached site-built ADU in Fresno runs $180,000 to $320,000, while prefab options typically land between $150,000 and $280,000. A JADU conversion runs $50,000 to $150,000. Plan-only services cost $4,000 to $12,000. The main variables are square footage, site access, soil conditions, finish level, and whether your electrical panel needs an upgrade. Call (559) 206-2363 for a written quote specific to your lot.
Yes. Benson ADU Fresno is authorized to build with Abodu, Cover, and Dvele, and we also work with James Hardie cladding for site-built units. Each brand has different strengths: Abodu for design-forward factory-built units, Cover for precision steel-framed panels, and Dvele for energy performance. We’ll help you compare them against site-built options before you commit.
Yes. We regularly take over stalled or abandoned ADU projects in Fresno. The first step is a site assessment to determine what’s built correctly, what needs to be removed, and what the permit status is. From there we’ll give you a written price to finish the job. Call (559) 206-2363 and we’ll schedule a walkthrough.
If any part of your ADU build isn’t done right within one full year of completion, we make it right. The promise is written into your contract and stamped on your project file. It covers workmanship and any covered repair that fails; a free second visit is included. It’s not a verbal promise; it’s on paper.
Have your property address ready, a rough idea of your budget, and any existing survey, floor plan, or ADU drawings you may already have. Knowing how you plan to use the unit (rental, family, workspace) helps us guide design and size. You don’t need to have anything else ready; we’ll handle the site assessment, panel check, and setback verification during the visit.
Schedule Your ADU Builders Service in Fresno Today
You deserve a builder who puts the price in writing, shows up when they say they will, and stands behind the work for a full year. Call Benson ADU Fresno at (559) 206-2363 for a no-obligation estimate on your ADU project. A live person answers, day or night, and your first site visit is free.
Written by Troy Eastman, Owner at Benson ADU Fresno, serving Fresno since 2006.



