Home Additions & ADU in Placerville - One Fixed Price, Permits Handled

Fast, Reliable Home Additions & ADU Across Placerville

Home additions and ADU construction in Placerville typically run $45,000-$130,000 for a room addition and $90,000-$220,000 for a fully permitted detached ADU, with garage conversions landing between $30,000-$80,000. Those are real numbers for this market, not national averages. We know Placerville because we work here constantly - from the historic grid near Main Street up through the hillside lots off Mosquito Road and Green Valley Road. Before any ground breaks, we’re looking at your foundation, your slope, and what’s underneath: this town sits on Gold Rush-era ground, and that changes how additions get built. Call (877) 610-1318 and Tom or one of his sons will talk you through what’s actually involved.

Call (877) 610-1318

Why Barrett & Sons Construction Is Placerville’s Preferred Home Additions & ADU Company

Tom Barrett started this company in 1998, and he’s the one who answers when you call. Not a sales rep, not a call center. His sons run the crews, and they’re on-site most days here in Placerville. When a homeowner off Broadway or up near Texas Hill Road has a question mid-project, they get an answer from someone whose name is on the truck.

We publish our license number, our address, and Tom’s name. You can look all of it up before you sign anything. That’s the point. After 29 years, our reputation in El Dorado County is built on written scopes, written change orders, and permits pulled on every eligible job. No surprises at the end. The permit inspector works for you, not for us, and that’s exactly how we like it. If you’ve been burned by a contractor who quoted one price on the phone and handed you another bill at the door, you’ll notice the difference within the first conversation. Every job comes with our written 90-Day Done Right Promise: if it’s not right, one call brings Tom back.

Our Home Additions & ADU Services in Placerville

We’re the Home Additions & ADU team that handles everything from first sketch to final inspection. Here’s what we do most often for homeowners in Placerville.

ADU Design & Permitting

In Placerville, ADU permits go through El Dorado County, and the process has quirks that out-of-town contractors miss. Slope setbacks, septic setbacks if you’re outside city sewer, and the Cal Fire wildland-urban interface requirements all apply differently depending on your exact parcel. We handle the full design and permitting package, including soil borings and geotech reports when the county requires them - and near the historic downtown, they often do. An ADU on a lot off Cedar Ravine or Canal Street isn’t a template job. We treat it that way.

Garage Conversion ADU

Converting an attached or detached garage into a legal ADU in Placerville usually runs $30,000-$80,000. The older the garage, the more the foundation drives the number. Many 1950s and 1960s homes in the 95667 ZIP have garage slabs poured without footings rated for living space, so we’re often underpinning or pouring new footings before framing begins. We also handle the tricky parts: separating utilities, adding egress windows, and bringing the structure up to current energy code. A garage conversion off Pleasant Valley Road is a different animal than one on a flat lot in Diamond Springs, and we price it that way from the start.

New Detached ADU

Building a brand-new detached ADU in Placerville runs $90,000-$220,000, depending on size, site prep, and finish level. Most of our Placerville ADU projects are on sloped lots, which means retaining walls, drainage, and foundation engineering are part of the real cost - not a surprise line item later. We put every scope item and every allowance in writing before work begins. An allowance that isn’t on paper is a surprise waiting for a date. Our Home Additions & ADU crew also coordinates utilities, septic or sewer hookups, and the final inspection sign-off. No loose ends.

Junior ADU & Interior Conversion

A Junior ADU (JADU) is the most affordable path to an accessory unit: you’re converting existing interior space, typically a bedroom plus bathroom, into a small independent unit. In Placerville, JADUs run roughly $45,000-$90,000 when plumbing and electrical are already nearby. The lower number assumes you have space in an existing footprint. We’ve done JADUs inside historic homes on Main Street where the challenge is working around century-old framing and keeping the original character intact. It’s slower work, but it’s the right way to do it.

Many homeowners adding an ADU also take the opportunity to update the main house. We handle Kitchen Remodeling in Placerville and Bathroom Remodeling in Placerville, which often share walls or utilities with the new addition. If you’re already opening up a wall for a second-story addition, it’s the natural time to plan both.

Trusted Brands We Service in Placerville

You’ll see Simonton windows, Ply Gem siding, and PGT impact-rated glass on our Placerville projects. We stock common parts and materials locally in El Dorado County, so we’re not waiting two weeks on a truck from somewhere else. If we’re doing a sunroom or enclosed patio addition, the window and door package gets selected early and locked into the written scope. That way the Andersen or Simonton units specified at contract are the ones that show up on delivery day. Named brands only - materials you can look up, not mystery products off a van.

Common Home Additions & ADU Problems We See in Placerville Homes

• Mine shaft subsidence near the historic core. Placerville’s downtown and surrounding blocks sit above undocumented 19th-century mine tunnels and adits. Before any addition or ADU foundation work, we recommend soil borings and a geotech report. It’s a standard step here, and it saves property owners from discovering a void the hard way.
• Cut-and-fill foundation movement on hillside lots. Almost no lot in Placerville is flat. 1950s-1980s ranch homes built on cut-and-fill slopes experience seasonal movement from heavy winter rain on clay-heavy decomposed granite soils. Any room addition or second-story project needs a foundation plan that accounts for that movement, not one copied from a flat-lot template.
• Chapter 7A ignition-resistant requirements. Virtually all of the 95667 ZIP falls within Cal Fire’s State Responsibility Area, which means additions and ADUs must meet ember-resistant vent, non-combustible eave, and Class A roofing standards. Contractors who work mostly in Folsom or Carmichael don’t carry this in their instinct. We do.
• Snow load on roof structures. Placerville sits around 1,900 feet in the Sierra foothills. Enough snow accumulates each winter that roof framing on second-story additions and ADUs must account for 20-40 psf snow loads. That’s a structural requirement that doesn’t exist 30 miles downhill in Sacramento, and we engineer for it every time.

Pricing for Home Additions & ADU in Placerville, CA

We Also Serve Cities Near Placerville

Our crews work throughout the foothills and into the valley. We regularly build additions and ADUs in Placerville, Diamond Springs, Cameron Park, El Dorado Hills, and Folsom. If you’re just outside the city limits and wondering whether we cover your road, call (877) 610-1318. The answer is usually yes.

FAQs - Home Additions & ADU in Placerville