Free written scope consultation - allowances, timeline, and change-order rules on paper before a single trade is scheduled
Fast, Reliable Home Additions & ADU Across Laguna
In Laguna, most home additions and ADUs run between $45,000 and $130,000 depending on scope, and the biggest variable isn’t labor cost. It’s the approval sequence. In ZIP 95758, your project typically has to clear Sacramento County or City of Elk Grove permitting plus HOA architectural review, often weeks before a permit is even submitted. Get that sequence wrong and you’ll watch a finished design sit on a desk while the clock runs. We handle the whole file, in order, so the work doesn’t stall halfway through. Call (877) 610-1318 and we’ll walk you through what your specific street and parcel require.
Why Barrett & Sons Construction Is Laguna’s Preferred Home Additions & ADU Company
Tom Barrett started this company in 1998, and he still publishes his name, his address, and his license number. In Laguna, that matters more than most places. You’re not just hiring a crew; you’re hiring someone who has to look your neighbors in the eye at the grocery store. We’ve built additions and ADUs throughout Laguna West and the surrounding planned communities, and we’ve learned the hard way that the architectural review board wants a complete submittal packet, not a sketch on a napkin. Our reviews from Laguna customers consistently mention the same thing: the written change order showed up before the new scope did, and nobody had to chase us for a permit update. Our teams are coordinated from our Sacramento office, and crews serve Laguna directly. When you call, a live person answers, not a voicemail box.
We’re not a franchise dispatching strangers. Tom’s sons run the crews. The same faces who walk your property for the estimate are the ones who show up with the plans, the permit packet, and eventually the hammers. If something goes wrong after the job, one call brings Tom back. That’s in writing on every contract, not buried in fine print.
Our Home Additions & ADU Services in Laguna
ADU Design & Permitting
This is where most Laguna ADU projects succeed or die. We file HOA architectural review first, then the city or county permit, then engineering for your slab. In Laguna West and other HOA-governed neighborhoods, skipping step one means the review board rejects your roofline or exterior color and the whole permit stalls for weeks. We assemble the submittal packet: site plan, elevations, materials list, color samples, grading notes. Then we track it through every review cycle until you have a signed permit in hand.

New Detached ADU
Detached ADUs in Laguna typically run $90,000 to $220,000. That range covers a one-bedroom unit with a kitchenette and bath up to a two-bedroom with full appliances. On a Laguna West home, our crew added a 576-square-foot detached ADU over a post-tension slab. We pulled the HOA’s architectural approval first, then engineered the foundation as an independent perimeter footing to avoid stressing the existing slab. The original garage floor never cracked. That’s the difference between planning around the slab and hoping for the best.

Garage Conversion ADU
Converting an existing garage runs $30,000 to $80,000 in Laguna, and it’s often the fastest path to a rentable unit because half the structure already exists. The catch here is the same one that trips up everyone else: you cannot trench new drain lines through a post-tension concrete slab without X-ray imaging to map the tendons. Hit a tendon and you’ve blown the slab’s structural design. We bring in the imaging, locate the safe paths, and if the plumbing can’t move where you want it, we tell you before we cut, not after.

Junior ADU & Interior Conversion
A junior ADU, usually under 500 square feet, can convert an existing bedroom or bonus room into a self-contained unit with its own entrance and kitchenette. In Laguna’s tract homes built between the late 1980s and mid-2000s, these conversions often hinge on whether the existing wall can accommodate the rough-in without disturbing the slab. Sometimes it can, sometimes it can’t. We bring an engineer’s sign-off to every answer, because in the adobe clay belt around Laguna, the slab is doing more work than it looks like.

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 Laguna
We stock and install windows and doors from Simonton, Ply Gem, and PGT. These aren’t mystery brands off a van. Our Home Additions & ADU team uses them because they’re specified in half the HOA architectural guidelines across Sacramento County, and they hold up through the Valley’s sustained 100-degree July stretches. For Laguna customers, we match the window and door package to what your review board already accepts, which shortens the approval timeline and keeps the exterior looking like it belongs on your street. If a window arrives with a factory defect, we handle the warranty claim with the manufacturer directly, same week, not “whenever the rep gets back.”
Common Home Additions & ADU Problems We See in Laguna Homes
- Submitting city permits before HOA architectural review. The HOA rejects the roofline or exterior color, and the project shuts down for weeks while you re-file. In Laguna West and the surrounding planned communities, this is the single most common stall we’re called in to fix.
- Cutting into a post-tension slab for plumbing rough-in without X-ray imaging. Hit a tendon and the slab’s structural integrity is gone. The repair is expensive, and the original engineering no longer applies. This is a preventable error, not an unavoidable one.
- Starting foundation excavation in February. Tule fog and rain-saturated adobe clay turn the excavation into slurry. You’ll end up re-grading, and that’s a change order you didn’t need. Summer may be hot, but it’s predictable; February is a gamble.
- Underestimating the review calendar. In Laguna, HOA architectural review can add three to six weeks before a permit is even submitted. Plan for it up front, or schedule your move-in date twice. We build the review timeline into the project calendar from day one.
Pricing for Home Additions & ADU in Laguna, CA
Here’s what we see on actual Laguna jobs:
| Project Type | Typical Laguna Range |
|---|---|
| ADU Construction | $90,000 - $220,000 |
| Garage Conversion | $30,000 - $80,000 |
| Home Addition | $45,000 - $130,000 |
| ADU Site Prep & Utilities | Bid per parcel - clay soil and post-tension slabs change the scope; free estimate covers exact number |
What drives the number? Foundation engineering on adobe clay, whether the slab is post-tension, how far the new utilities have to run, and what the HOA will approve. Laguna’s shrink-swell clay means we often pour deeper, wider footings here than crews use in foothill cities an hour east. That’s not a markup. That’s the soil telling us what it needs. Call (877) 610-1318 for an exact line-item quote. Estimates are free, and every number arrives in writing before anything gets signed.
We Also Serve Cities Near Laguna
Our crews cover Laguna and the surrounding communities regularly. If you’re in Elk Grove, Parkway, Florin, or Vineyard, you’ll get the same crew, the same written change orders, and the same live human on the phone. We’ve done work across this stretch of Sacramento County long enough that the permit counter staff knows our paperwork. And we know which projects in each city hit which snag. Learn more about Home Additions & ADU in Laguna, or check Home Additions & ADU for the full scope of what we build.
Serving Laguna, CA - Our Local Coverage Area
We’re based in the Laguna 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 Laguna
Yes. In Laguna West and most other HOA-governed communities in ZIP 95758, the architectural review board typically needs to sign off on your roofline, exterior colors, materials, and setbacks before the city or county will accept a permit application. We prepare and file the HOA submittal first, then submit the building permit, then start engineering. Skipping that order is the most common way Laguna projects stall for weeks. Call (877) 610-1318 and we’ll tell you exactly what your particular HOA requires, in writing, before you spend a dollar.
Not safely without X-ray imaging first. Post-tension concrete slabs have steel tendons running through them under tension. Cutting blind risks hitting a tendon, which releases the tension and compromises the structural design of the entire slab. We image the slab, map the tendon locations, and then either route the drains around safe zones or, where that’s not possible, re-engineer the addition with an independent perimeter footing instead of tying into the existing slab. It adds a few days to the timeline and it’s the only safe way to do it. Call (877) 610-1318 and we’ll explain what applies to your specific floor plan.
Typically three to six weeks, on top of the city permit timeline. Laguna’s HOA boards in the planned communities meet on a set schedule, and a second-story addition triggers the full review because it changes the roofline and the sightline from the street. If your submittal packet is incomplete on the first pass, you’ll get knocked to the next meeting cycle. We file complete packets - elevations, color samples, materials, and grading notes - so your project gets through in one cycle, not three. Call (877) 610-1318 for a realistic calendar on your specific project.
Because Laguna sits in the Sacramento Valley’s adobe clay belt. This soil expands when wet and shrinks when dry, and that movement is relentless. A footing that works on the decomposed granite in Folsom or Roseville will move here unless it reaches below the active clay zone. For detached ADUs in Laguna, we typically engineer an independent perimeter footing that sits deeper than what a foothill town would require. That’s not overbuilding. It’s building for the ground that’s actually here. Call (877) 610-1318 and we’ll show you the soil report that drives the design.
Usually not, in Laguna. Most patio slabs here are 3 to 4 inches thick with no reinforcement, poured as flatwork inside a post-tension foundation. They were never designed to carry the weight of a roof, walls, and glazing. Building a sunroom on that slab risks cracking the slab and pulling the house wall with it. In most cases we pour a new perimeter footing or, where the HOA and parcel allow, install a reinforced slab thickened at the edges. It costs more up front and it keeps the structure standing for 25 years. Call (877) 610-1318 for a free look at your patio slab and an honest answer on what it can carry.
If you’re planning an addition or ADU in Laguna, don’t guess at the sequence. The order is HOA first, permit second, engineering third, and the clay soil and post-tension slab under your house decide the rest. Call (877) 610-1318 to schedule your free estimate. You’ll get a written line-item price, a real calendar, and the name of the person who’ll be standing on your job site.
Written by Tom Barrett, Owner at Barrett & Sons Construction, serving Laguna and the surrounding Sacramento County communities since 1998.







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