Free written scope consultation - allowances, timeline, and change-order rules on paper before a single trade is scheduled
Fast, Reliable Home Additions & ADU Across Fresno
A home addition or ADU in Fresno typically runs $45,000-$130,000 for a room addition, $90,000-$220,000 for a new detached ADU, and $30,000-$80,000 for a garage conversion. Those are the real numbers our Fresno customers work with, and we’re happy to walk you through every line item before you sign anything. Call (877) 610-1318 and Tom or one of his sons will walk your lot with you and tell you straight what your project needs on Fresno’s soil.
We grew up building in the San Joaquin Valley. We know what Fresno’s clay does to a slab in August and what Tule fog does to a schedule in January. Most of our crews live within twenty minutes of the city, so when you call about a footing or a stucco tie-in, you’re talking to someone who drives past your neighborhood every week.
Why Barrett & Sons Construction Is Fresno’s Preferred Home Additions & ADU Company
Barrett & Sons has been owner-operated since 1998. Tom Barrett answers his own phone when you call, and his sons run the crews on most Fresno jobs. That matters here because Fresno isn’t a market where you can hand a project to a rotating cast of subcontractors and hope the clay cooperates. Our Home Additions & ADU team knows the difference between a clean soil report and a clean-looking soil report. We pull permits on every eligible Fresno job. We get inspections signed. We hand you a written change order before any scope moves. And we back every job with the 90-Day Done Right Promise: if it’s not right, Tom comes back and makes it right. One call.
Our Fresno customers check us out before they hire us. Tom’s name, address, and license number are published and verifiable. Call the license board. Look up the number. Ask anyone in 93706 or out by the 93718 parcels if the Barrett crew kept their word. The answer is usually yes.
Our Home Additions & ADU Services in Fresno
ADU Design & Permitting
Every ADU in Fresno starts with the same conversation: what does the soil under your lot actually look like? Most west Fresno parcels and parts of the older central neighborhoods carry shrink-swell clay that moves seasonally. We work with the geotechnical engineer, pull the permits, and design the ADU so the slab, drainage, and setbacks work with the land instead of fighting it. Permits get pulled before any work begins, and the inspector signs off at each stage.

Garage Conversion ADU
Fresno garage conversions cost between $30,000 and $80,000, depending on whether the existing slab can be reinforced, what the electrical panel can carry, and what Title 24 upgrades the conversion triggers. The older wood-frame garages in Fresno’s post-WWII neighborhoods were never built as living space, so we check the footing depth, the roof load path, and the sewer line location before we quote. 93706 and parts of 93702 have old farmland fill under them, and we don’t pour on top of that without deep borings.

New Detached ADU
A new detached ADU in Fresno runs $90,000-$220,000. That’s a wide spread for a reason: the lot prep matters more than the framing. Fresno’s expansive clay has to be conditioned or over-excavated before the first yard of concrete arrives. We schedule pours before 10 a.m. in summer, because hot afternoon concrete flash-hydrates at the surface and leaves you a weak slab. We specify cool-roof materials and high-R insulation to meet Climate Zone 13 without turning your ADU into an oven by July.

Junior ADU & Interior Conversion
Converting an existing interior space inside a Fresno home, whether that’s a finished portion of the house, an attached room, or a permitted interior ADU, is the fastest path to extra square footage when the foundation is already sound. These projects live and die on the connection details: how the new plumbing ties into the old cast-iron drain lines, how the stucco seam between new and old moves independently, and how the existing slab handles the added point loads. We treat every interior conversion like an addition, which means written change orders before any wall moves.

What happens when you call
- 1
A real person answersNo phone trees - you reach a local pro.
- 2
You get an upfront price rangeHonest numbers before anyone is dispatched.
- 3
A background-checked tech heads outLicensed & insured, dispatched right away.
- 4
You approve before work beginsNothing starts until you say go.
Trusted Brands We Service in Fresno
We specify materials you can look up. On Fresno ADUs we lean on Simonton windows because the thermal performance holds up in Climate Zone 13, and we use Ply Gem exterior profiles for stucco transitions that won’t separate the first time the clay heaves. No mystery brands off a van. We stock common profiles locally so Fresno homeowners aren’t waiting three weeks for a backordered frame. If you’re comparing quotes, ask the other contractor which window brand they’re specifying. If they can’t answer, walk.
Common Home Additions & ADU Problems We See in Fresno Homes
- Footings poured on un-remediated expansive clay. The soil swells in wet winters and shrinks when summer hits 110°F. New room additions twist off square within two seasons if the footing wasn’t designed for that movement.
- Stucco tie-ins cracking at the original house seam. A new ADU slab moves independently of the old foundation. If nobody planned an isolation joint and a flexible stucco transition, that seam opens up within the first year and keeps moving.
- Hot-weather concrete pours failing before framing starts. After 10 a.m. in a Fresno summer, the surface flash-hydrates. You get a dusty, weak slab that spalls under load. We schedule around it, not through it.
- Old farmland fill that doesn’t show on standard soil reports. West Fresno parcels, especially 93706, can hold organic-rich fill layers from irrigated agriculture. Footings poured without deep borings on that ground settle differentially within five years.
Pricing for Home Additions & ADU in Fresno, TX
Our Fresno pricing breaks down like this:
| Project Type | Typical Fresno Range |
|---|---|
| ADU Construction | $90,000 - $220,000 |
| Garage Conversion | $30,000 - $80,000 |
| Home Addition | $45,000 - $130,000 |
What moves the number? Soil condition first, then square footage, then finish level. A room addition on clean, stable soil in a newer east Fresno development costs less than the same square footage on west Fresno’s old farmland fill, because the fill work and deep borings add real prep cost. The cheap slab quote that skips the borings will cost more than the honest quote within five years. We’d rather give you the honest number up front. Call (877) 610-1318 for a free written estimate, no trip charge inside the county.
We Also Serve Cities Near Fresno
Our crews handle Home Additions & ADU in Fresno and the surrounding communities. We’re also on job sites in Sienna Plantation, Missouri City, Manvel, and Stafford most weeks. If you’re close to Fresno but not inside the city limits, call anyway: dispatch and scheduling run from our Houston office, and crews serve the whole area locally.
Serving Fresno, TX - 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.
FAQs - Home Additions & ADU in Fresno
Fresno sits on San Joaquin Valley alluvial soils with high shrink-swell clay, and nearly every slab-on-grade home built here since the 1950s sits on ground that moves seasonally. Wet winters expand the clay; 110°F summers contract it. Coastal contractors don’t deal with that cycle. We call for deep borings on any Fresno project where the standard soil report doesn’t reach the organic layers or the water table anomalies common in old farmland areas. Call (877) 610-1318 and we’ll explain what your specific lot needs.
Climate Zone 13 is one of the most thermally demanding zones in the state, which means your second-story addition triggers strict cool-roof, high-R insulation, and HVAC efficiency requirements. That adds real cost versus a coastal build, but it also means a properly designed Fresno addition stays habitable in August without a second AC unit running constantly. We spec for Zone 13 from day one so the permit doesn’t bounce and the upstairs doesn’t bake.
Yes, in most of Fresno you need a soils report for a garage conversion ADU, because the existing slab was poured as a garage slab, not a living-space slab, and it may sit on unremediated expansive clay or old farmland fill. Parts of 93706 and 93702 have organic-rich layers that don’t show on standard reports. We won’t pour a new stem wall on that ground without borings, because the neighbor who skipped them now has a 3/8-inch crack at the stem wall and a conversion that’s settling.
Most Fresno ADU projects follow a milestone draw schedule: deposit at contract, a draw at foundation or slab completion, a draw at framing and rough-in, and a final draw at inspection sign-off and turnkey. Every change to the scope or allowance lands as a written change order before work proceeds. That’s not negotiable with us. Call (877) 610-1318 and we’ll walk you through a sample draw schedule for your specific project.
Because the new slab moves independently of the original foundation, and if nobody planned an isolation joint and a flexible stucco transition at that seam, the seasonal clay movement opens it up fast. We see it on additions across Fresno’s older neighborhoods, especially where the original house was built in the 1950s and the addition went in on a fresh slab decades later. The fix is in the detailing before the stucco goes on, not in caulking after the crack appears.
Key Takeaways
- Fresno home additions typically run $45,000-$130,000; ADUs run $90,000-$220,000; garage conversions run $30,000-$80,000.
- Expansive clay and old farmland fill make soil prep the most important line item on any Fresno project.
- We pull permits, get inspections signed, and issue written change orders before any scope change.
- You can call (877) 610-1318 and a live person answers, not a voicemail box. No trip charge inside the county.
Written by Tom Barrett, Owner at Barrett & Sons Construction, serving Fresno and the surrounding communities.







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