Fast, Reliable Garage Conversion ADU Across Foothill Farms
Garage conversion ADUs in Foothill Farms typically run $145,000-$230,000 all-in, drawings through final inspection, depending on whether you’re converting an attached or detached garage and whether a bathroom addition means trenching the original slab. That’s the honest range before anyone opens a wall. The bigger variable in Foothill Farms isn’t square footage. It’s what the 1950s and 1960s construction hides: undersized panels, missing vapor barriers, and setbacks that were legal when the garage went up but aren’t anymore. We’re Ellery ADU Studio, and we design, permit, and build garage conversions under one contract at one written price. Call (971) 497-2402 and we’ll walk the property with you, no charge for the estimate.

Why Ellery ADU Studio Is Foothill Farms’s Preferred Garage Conversion ADU Company
The reason Foothill Farms homeowners call us isn’t a jingle or a billboard. It’s that we can name what’s inside your garage walls before we open them, because we’ve opened dozens of them in this exact neighborhood. A 1962 ranch off Andrea Boulevard has the same 60-amp sub-panel as a 1958 original on Myrtle Avenue. The slab conditions off Elkhorn Boulevard mirror what we find off Walerga Road. That pattern recognition matters when a permit review or an opened wall changes the scope, and it’s why our clients don’t get blindsided.
We’ve designed, permitted, and built 900+ ADUs since 2015, every one governed by The Haven Standard. That means a written price before work starts (Clause 1), a documented photo record on every visit, and a 365-Day Done Right Promise: if the finished ADU doesn’t match the permitted drawings, we make it right, in writing. Scheduling for Foothill Farms is coordinated from our Sacramento office, and crews work locally. We see Foothill Farms as what it is: unincorporated County, not a city, with its own rules and its own surprises.
Our Garage Conversion ADU Services in Foothill Farms

Detached Garage Conversion
Most Foothill Farms homes have detached single-car garages at the back of the lot, and those are the strongest conversion candidates. The County’s ADU ordinance allows a 4-foot rear and side setback, which is more forgiving than many adjacent cities. But if your 1950s garage was built at 3 feet or less from the rear property line, BSAS may flag it as nonconforming. We confirm setback status before we draw anything, so the design doesn’t promise square footage the County won’t approve.
Detached garage conversions in Foothill Farms typically run $160,000-$230,000 when they include a kitchen, bath, and separate utility connection. That assumes we’re trenching for sewer, adding a 100-amp sub-panel, and installing a ductless mini-split; all of which we price before permit submittal.

Attached Garage Conversion
Converting an attached garage off the main home’s hallway is usually the most cost-efficient path, since you’re already inside the house’s thermal envelope and electrical service. Foothill Farms attached garages from the 1950s and 1960s are often sheetrocked on finished walls, which makes inspection cuts faster. The tradeoff is that the conversion pulls the garage out of the house’s existing footprint, so we’re careful about fire separation at the new demising wall. Attached conversions here typically run $145,000-$195,000 depending on bath and kitchen scope.

Garage Partition & Bathroom Add
Some Foothill Farms owners don’t want a full ADU. They want the garage split: one bay stays for storage or a workshop, the other becomes a permitted studio with a bathroom. The County treats this as an ADU if it has a kitchen or a bath and a separate entrance, so the permit path is the same. The big cost driver is the slab work. Original 1950s garage slabs in Foothill Farms have no vapor barrier, so when we trench for a 3-inch ABS bathroom rough-in, we almost always find moisture wicking that requires a 4-inch concrete overlay and waterproofing before finish flooring goes down. We write that allowance into the contract up front; it’s not a surprise at framing.

Carport Conversion
Carports are less common in Foothill Farms than full garages, but they show up on some 1970s-era lots. A carport conversion means new walls, new electrical, new foundation work; essentially a small new build under the ADU ordinance. Budget $120,000-$170,000 depending on site conditions, and expect the same County permit path as a detached conversion. We pull permits, we schedule inspections, and we don’t sign off until BSAS does.

What happens when you call
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A real person answersNo phone trees - you reach a local pro.
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You get an upfront price rangeHonest numbers before anyone is dispatched.
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A background-checked tech heads outLicensed & insured, dispatched right away.
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You approve before work beginsNothing starts until you say go.
Trusted Brands We Service in Foothill Farms
We specify and coordinate prefab and modular systems from Abodu, Cover, and Dvele when the project calls for it, and we do it inside the same single contract as the site work. That means no separate vendor warranty to chase; if the prefab module doesn’t meet the permitted drawings, our 365-Day Done Right Promise applies to it too. For Foothill Farms clients, we keep the delivery and craning logistics local, which matters on tighter lots off Walerga Road and Andrea Boulevard where access is tight.
Common Garage Conversion ADU Problems We See in Foothill Farms Homes

- Original 60-amp sub-panel cannot support the new load. A mini-split alone pulls real amperage; add an induction cooktop and a bathroom fan and the old panel trips constantly. We replace it with a 100-amp feeder and price the service change in the contract, not in a change order.
- Slab has no vapor barrier or insulation. When we trench for plumbing, the exposed concrete shows moisture wicking from the soil. We spec a 4-inch overlay and waterproofing before any finish flooring; skipping it means mold under the LVP within two years.
- Nonconforming rear setback gets flagged by BSAS. If the garage sits 3 feet from the rear line, the County may deny the ADU footprint as drawn. We confirm setback status during our first site visit, before drawings, so the design doesn’t collapse in plan review.
- Undersized or damaged framing hides behind drywall. Termite runs at the sill plate and roof rafters that span too far for the new load are common in 1950s and 1960s Foothill Farms garages. We open targeted inspection cuts, photograph what we find, and price the repair in writing before we touch it.
Pricing for Garage Conversion ADU in Foothill Farms, CA
Here’s the range, stated plainly. Attached garage conversions in Foothill Farms run $145,000-$195,000. Detached conversions run $160,000-$230,000. Carport conversions run $120,000-$170,000. A partition-and-bath addition inside an existing garage runs $85,000-$145,000. These figures include drawings, permit fees, construction, materials, and our documentation; they are line-itemed in the written scope before you sign anything. The single biggest cost swing is what the opened wall or the slab reveals, and our contract includes written allowances for exactly those items, priced and approved in writing before we proceed. Call (971) 497-2402 and we’ll give you a specific number for your property, free of charge.
We Also Serve Cities Near Foothill Farms

While we focus on unincorporated Sacramento County and the Foothill Farms area specifically, our crews also run projects in Los Angeles, San Diego, San Jose, and San Francisco. If your property sits outside Foothill Farms proper, our Garage Conversion ADU team can confirm coverage and scheduling from our Sacramento office. See also Garage Conversion ADU in Foothill Farms for the county-specific permit path we follow here.
Serving Foothill Farms, CA - Our Local Coverage Area
We’re based in the Foothill Farms 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 - Garage Conversion ADU in Foothill Farms

Sacramento County’s ADU ordinance allows a 4-foot rear setback, but a garage built at 3 feet is nonconforming, and BSAS may flag it during permit review. In practice, the County sometimes allows the conversion to proceed if the nonconforming condition predates current code, but if the structure is flagged, the fix is to re-frame the wall inward to 4 feet, which shrinks the footprint and may save the project from a variance. We confirm status before drawings so the design matches what the County will actually approve. Call (971) 497-2402 for an exact assessment of your lot.
Because the original homes were built with 60-amp sub-panels serving a single garage door opener and one light bulb. A code-compliant ADU with a mini-split, cooktop, refrigerator, and bathroom fan exceeds that capacity the moment everything runs at once. The fix is a 100-amp feeder and a new sub-panel, and we write that line item into the contract before the project starts. It’s not a surprise; it’s a pattern we see on nearly every Foothill Farms conversion.
We stop, photograph what we found, and write a scope line for the repair: sistered studs, a replaced header, termite repair at the sill plate, or whatever the specific condition demands. You approve the number in writing before we cut further. Our contract includes written allowances for exactly this scenario, because a 1950s garage that hasn’t been opened in 60 years rarely opens clean. No door-side upsells, no scope creep; Clause 5 of The Haven Standard.
Yes, but expect the slab work to be more than a simple trench. Original Foothill Farms garage slabs have no vapor barrier, so when we cut for the 3-inch ABS rough-in, we usually find moisture wicking from the soil. The fix is a 4-inch concrete overlay and waterproofing before finish flooring; skipping it means mold under the floor within two seasons of Tule fog and winter freeze-thaw. We price the overlay as a written allowance in the contract, not as a change order mid-project.
Sacramento County treats mechanical cooling as a habitability requirement for ADUs, and a window unit does not meet the County’s standard for a permitted dwelling. A ductless mini-split is the baseline expectation, and in Sacramento Valley summers that routinely top 100°F for weeks, it’s also the only honest way to keep the space livable. We spec and install them as standard on every Foothill Farms ADU, and the cost is in the written price from day one. Call (971) 497-2402 for an exact quote on your project.
Written by Nadia Ellery, Owner at Ellery ADU Studio, operating in Foothill Farms and unincorporated Sacramento County since 2015.