Free written scope consultation - allowances, timeline, and change-order rules on paper before a single trade is scheduled
Fast, Reliable Home Additions & ADU Across El Dorado Hills
If you’re weighing a home addition or ADU in El Dorado Hills, the honest price most homeowners in 95762 will see runs roughly $45,000 to $130,000 for a standard addition, and $90,000 to $220,000 for a new detached ADU. Those numbers move based on hillside access, fire-zone materials, and what the dirt gives up when we start digging. This page was written for people who live here, not for a national website template. If you’d like Tom Barrett to walk your lot and put a real price on your project, call (877) 610-1318. We answer the phone.
Why Barrett & Sons Construction Is El Dorado Hills’s Preferred Home Additions & ADU Company
Barrett & Sons Construction has been owner-operated since 1998, with Tom Barrett and his sons on job sites most days. That matters in El Dorado Hills because this terrain punishes contractors who bid from a flatland playbook. We work the decomposed granite and shrink-swell clay across 95762 regularly, so when we give a quote on a second story addition near Francisco Drive or a garage conversion above Green Valley Road, the number already accounts for what the ground will likely do. El Dorado Hills homeowners call us because we don’t send strangers. The crew members who show up carry the Barrett & Sons name, and they’ve been background-checked. Tom Barrett publishes his name, his address, and his license number. Look it up before you sign anything.
Our Home Additions & ADU team works this ZIP week in and week out. We know the El Dorado County permit counter, the fire marshal’s expectations, and how to schedule inspections so a finish doesn’t stall for three weeks. When you call (877) 610-1318, a live person picks up, 24/7. Not a voicemail box. Not an out-of-state call center.
Our Home Additions & ADU Services in El Dorado Hills
We do the full range of residential additions and ADU work across El Dorado Hills. The four below cover most of what 95762 homeowners ask about, but if you’re planning something bigger, call and we’ll put it on paper.
ADU Site Prep & Utilities
Most El Dorado Hills lots are not flat. Site prep here means benching into a slope, managing retaining walls, and running utilities across terrain where granite sits shallow. We handle grading, trenching to the uphill or downhill side, sewer and water stub-outs, and panel upgrades. On one hillside lot near Francisco Drive, our crew staged a detached ADU build around a 14-inch granite boulder we hit at 16 inches down while excavating the foundation. That meant jackhammer time and a revised footing plan before the rough-in inspection. We logged the rock removal as a written change order before the work happened, and the build stayed on budget.

New Detached ADU
Building a detached ADU in El Dorado Hills means starting with the Wildland-Urban Interface code. Chapter 7A of the California Building Code applies to nearly every new structure in the 95762 high and very high fire hazard zones. That means ember-resistant vents, ignition-resistant or non-combustible siding, and Class A roofing on the new unit. We price those materials up front, not as a surprise at rough-in. A detached ADU here commonly runs $90,000 to $220,000 depending on size, slope, utility runs, and fire-hardening requirements.

Garage Conversion ADU
Converting an existing garage is usually the most affordable path to an ADU in El Dorado Hills, typically $30,000 to $80,000. The caveat on 1990s and 2000s tract homes here is that the slab may not have a moisture barrier, and the existing walls were not built to today’s fire-zone exterior standards. We assess the foundation, the electrical panel, and the roof assembly before we quote. In some cases the garage’s existing stucco qualifies as ignition-resistant, which keeps the price down. In others, we replace the garage door opening with a Chapter 7A-compliant wall assembly and new windows.

Second Story Additions
Adding a second story in El Dorado Hills is more complex than in flat Sacramento Valley suburbs. The footing that supported a single-story 1995 home was not sized for two. Seasonal soil movement from the shrink-swell clay means we often need to reinforce the foundation before framing upward. We’ll look at the retaining walls, check for past slope movement, and pull the original plans if they exist. A second story addition here typically falls in the $45,000 to $130,000 range depending on square footage, structural reinforcement, and fire-rated assembly requirements.

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 El Dorado Hills
We carry material lines you can look up and verify, not mystery stock off a van. On ADU and addition projects in El Dorado Hills, we regularly install Techo-Bloc and Cambridge pavers for hardscape and driveway edges, and use Oldcastle and Quikrete products for footings, stem walls, and flatwork. When you want a paver patio tied into your new ADU entry, or a retaining wall rebuilt as part of a site prep scope, we spec brands with published performance data. That matters on hillside lots where the freeze-thaw cycle and summer heat put stress on concrete products. You’ll see the brand names on the written scope before work starts, and the price won’t change unless you sign a written change order.
Common Home Additions & ADU Problems We See in El Dorado Hills Homes
Every foothill community has its own version of the same five headaches. Here’s what shows up most often in 95762.
- Shallow granite and boulders. Excavation crews working El Dorado Hills hillside lots routinely hit bedrock or granite boulders 12 to 18 inches down. Sacramento valley contractors underbid this constantly because they don’t price jackhammer time or rock removal, then hand the owner a surprise invoice.
- Chapter 7A fire-zone compliance failures. Missing the ember-resistant vent requirement or using untreated siding on a new addition means a failed inspection, reorder delays, and sometimes tear-out. We’ve corrected enough of these to know the fire marshal’s checklist by heart.
- Neighbor conflict on tight lots. Blocking a shared driveway or running equipment past the county’s noise-window rules triggers complaints that stall permit sign-offs. We stage material drops around neighbors’ schedules and keep the right-of-way clear.
- End-of-life building envelopes. Much of El Dorado Hills was built in the 1990s and early 2000s, which means stucco, roofing underlayment, and deck connections are failing at the same time. A second story addition on a home with failing stucco means we’re opening walls anyway, so the scope should include what we’ll find behind them.
Pricing for Home Additions & ADU in El Dorado Hills, CA
Here are the real ranges we’re quoting in El Dorado Hills right now. These numbers assume a typical 95762 lot with normal access, but they move when slope, rock, or fire-zone upgrades enter the picture.
| Project Type | Typical El Dorado Hills Range |
|---|---|
| Home Addition (single story) | $45,000 - $130,000 |
| Second Story Addition | $45,000 - $130,000 |
| ADU Construction (new detached) | $90,000 - $220,000 |
| Garage Conversion ADU | $30,000 - $80,000 |
Three things push an El Dorado Hills addition higher than an equivalent project in Folsom or Orangevale: fire-zone Chapter 7A materials, hillside excavation that hits rock, and staging constraints on lots where the only level area is the driveway. We put every one of those in writing before the first day of work. No allowance exists off-paper. If we hit a boulder and need extra jackhammer time, you’ll see a written change order with the price before the hammer starts. The estimate is free. Call (877) 610-1318 and we’ll walk your lot together.
We Also Serve Cities Near El Dorado Hills
We work throughout the foothill corridor around El Dorado Hills, and our crews regularly take projects in Folsom, Cameron Park, Granite Bay, and Orangevale. If your property sits close to the county line and you’re not sure which jurisdiction applies, call us. We’ll figure out the permit path and give you a straight number. Dispatch and scheduling are coordinated from our Sacramento office, and the crew serving El Dorado Hills works locally, so you won’t wait on a team driving in from another county.
Serving El Dorado Hills, CA - Our Local Coverage Area
We’re based in the El Dorado Hills 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 El Dorado Hills
Building an ADU in 95762 means complying with California Building Code Chapter 7A because most lots sit in High or Very High Fire Hazard Severity Zones. In practice that means ember-resistant vents at the eaves and foundation, ignition-resistant or non-combustible siding, and Class A roofing on the new structure. These materials cost more than standard valley-spec finishes and add a fire marshal inspection to the permit path. We spec them up front so the fire inspection doesn’t fail and stall your finish. Call (877) 610-1318 and we’ll tell you exactly which materials your lot requires.
Expect an added $2,000 to $8,000 on most hillside excavations, depending on the size of the boulder and whether we need a rock hammer, a breaker attachment, or a revised footing plan. Slab-flat Sacramento-area crews almost never include this, which is why their initial bids look cheaper and then grow. When we quote an El Dorado Hills addition, the number already reflects the likelihood of hitting rock based on what we’ve seen on nearby lots. If we hit something unexpected anyway, you’ll get a written change order with the cost before we proceed. Call (877) 610-1318 for a site-specific estimate.
Yes. El Dorado County enforces noise and work-hour ordinances, and when your addition sits close to a neighbor’s wall or shares a driveway, we file a party-wall notice before doing anything that could affect their side. Blocking a shared driveway is the fastest way to get a complaint that stalls your permit. We schedule material deliveries around school drop-offs and neighbor parking patterns, keep the right-of-way clear every evening, and put the working hours in writing before we start. Call (877) 610-1318 and we’ll walk through how your specific lot will be staged.
Sometimes, but it depends on the slab and the fire-zone assembly. Many 1990s and 2000s tract homes in 95762 have garage slabs with no moisture barrier and exterior walls that weren’t built for habitable use. If the stucco qualifies as ignition-resistant and the roof is Class A, a garage conversion can go for the lower end of the $30,000 to $80,000 range. If the foundation needs cutting for plumbing or the wall assembly must be rebuilt to Chapter 7A, the price climbs. We’ll assess it honestly. The estimate is free. Call (877) 610-1318 and we’ll tell you what your garage can handle.
Access affects everything here. On a steep lot where the only flat staging area is the driveway, we schedule material drops in sequence rather than stockpiling everything at once, which can add schedule days but keeps the street clear and the neighbors sane. If a crane can’t reach the uphill side, framing costs shift because materials move by hand or by tracked equipment. These access constraints are baked into our El Dorado Hills quotes because we’ve worked enough hillside lots to know what the site will actually allow. Call (877) 610-1318 and we’ll price your specific access honestly.
Written by Tom Barrett, Owner at Barrett & Sons Construction, serving El Dorado Hills since 1998.







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