A free site visit, a check of what your lot allows and a written, line-item price.
Get your free estimateFast, Reliable ADU Builders Across Moraga
We build accessory dwelling units – backyard homes, garage conversions, and detached studios – for homeowners across Moraga who want more livable space without leaving their lot. If you’re searching for ADU Builders who understand Moraga’s hillside terrain, expansive clay soils, and the design review process, you’ve found a team that works here every week. A typical detached ADU in Moraga runs $280,000 to $520,000 depending on site conditions, finishes, and foundation requirements. Call (707) 760-0502 and we’ll give you a written price before any work starts.
Moraga isn’t Lafayette or Orinda when it comes to building. The slopes are steeper, the bedrock is shallower, and the town reviews hillside projects with real scrutiny. That local knowledge changes how we price, how we schedule, and how we engineer every ADU we build here. The Kingswell Guarantee applies to every job: written price first, real arrival window, clean job site, and a written guarantee delivered before we drive a single nail. Russ Delmar leads our crew, and he’ll be on site personally for your project.
Why Lodgewick ADU San Francisco Is Moraga’s Preferred ADU Builders Company
The Kingswell family has been building ADUs and home additions since 2010, and our Moraga clients consistently tell us the same thing: they’d been burned before by contractors who quoted a low number and changed it at the door. We don’t do that. Every project starts with a written price. Every project ends with a written guarantee. The 365-Day Done Right Promise means exactly what it says: if it’s not done right, we come back and make it right – in writing, on every build.
Moraga homeowners call us for the same reasons they call our San Francisco Bay Area office. A live person answers, 24 hours a day. Not a voicemail loop, not a chatbot. When you call with a question about your foundation engineering or your millwork lead time, you reach a human being who knows your project. That matters when you’re six figures into a build and you want a straight answer.
Our crews are background-checked and uniformed. You’ll know exactly who’s on your property on Camino Ricardo or Rheem Boulevard and when they’ll arrive. We show up in the window we gave you. We leave the site cleaner than we found it. That’s The Kingswell Way, and it’s how we’ve built our reputation across Moraga, Orinda, and the surrounding Lamorinda communities.
ADU Design in Moraga
ADU Design in Moraga means engineering for hillsides first and aesthetics second. Steep lots off Moraga Road and along Rheem Boulevard frequently sit on expansive clay that expands and contracts with seasonal moisture. Shallow bedrock lurks just below the surface on many parcels. Standard slab-on-grade foundations that work fine in flat parts of Contra Costa County can crack and shift on Moraga slopes. That’s why we start nearly every detached ADU design with a geotechnical report before we quote a final number.
Design also has to survive the town’s design review process. Moraga reviews hillside projects for slope stability, view impacts, and visual compatibility with the neighborhood. A design that ignores those triggers gets sent back for revision. We handle that paperwork and those conversations on your behalf. You shouldn’t have to learn planning department jargon to get your ADU approved.
Site Survey and Geotechnical Review
A proper hillside design starts with understanding what’s under your lot. Expansive clay and shallow bedrock change everything: foundation type, drainage plan, retaining wall specs, and ultimately the budget. We coordinate the reports and translate them into plain English so you understand why a pier-and-grade-beam foundation costs more than slab-on-grade and why spending that money up front protects the structure for decades.
Plans That Pass Review the First Time
Moraga’s design review process rewards specificity. We submit plans with slope analysis, erosion control details, and material specifications that anticipate the committee’s questions. Custom millwork drawings, window schedules, and exterior finish samples go in the packet from day one. It adds a week of prep and saves you months of back-and-forth.
Design costs for a Moraga ADU typically run $15,000 to $35,000 for plans, engineering, and permit submittal support. High-end designs with architectural glass and fully custom millwork run higher. You’ll know the exact number before we start drawing.
Backyard ADU in Moraga
Backyard ADU construction in Moraga is where foundations, drainage, and long-lead finishes collide. Most of the detached units we build here are 400 to 800 square feet on lots that slope, sometimes sharply. That means pier-and-grade-beam foundations, retaining walls in some cases, and careful stormwater management so winter rains don’t erode your hillside or flood your new unit. It also means scheduling around fabrication lead times for custom millwork and specialty glass, which often take longer than the framing and roofing combined.
Pier-and-Grade-Beam Foundations
On a steep lot off Camino Ricardo, our crew coordinated a geotechnical report that revealed expansive clay and shallow bedrock, so we engineered a pier-and-grade-beam foundation for a detached ADU. We managed the long-lead custom millwork and architectural glass from our own vendors, and the schedule was set by those fabricated items – not labor – so we locked a fixed price in writing before ordering anything. That’s the standard we bring to every Moraga backyard build.
If your lot needs piers and grade beams, expect foundation costs between $45,000 and $110,000 depending on depth, soil conditions, and access constraints. Flat-lot slab pricing doesn’t apply here, and any builder who quotes it without a geotechnical report is guessing.
Drainage and Erosion Control
Winter rains on Moraga slopes don’t just soak the ground. They move soil, pressure foundations, and find every weakness in a drainage plan. We install French drains, swales, and retaining walls where the slope demands them. Erosion control during construction keeps your hillside intact and your neighbors’ views protected. It’s part of every backyard ADU we build in Moraga, not an add-on we spring on you later.
Trusted Brands We Service in Moraga
We work hands-on with the ADU brands and materials that hold up on Moraga hillsides. For prefab and panelized ADU projects, we partner with Abodu and Cover, both of which offer designs that can be adapted to pier foundation systems when site soils require it. For exterior finishes that resist heat and fire risk in the inland Lamorinda valley, we specify James Hardie fiber cement siding and trim. We keep local Moraga projects moving by coordinating delivery windows, foundation interface details, and finish scheduling directly with these manufacturers. When a homeowner asks whether a prefab unit can work on their slope, we give a straight answer based on soil reports, not marketing brochures.
Common ADU Builders Problems We See in Moraga Homes
- Foundations quoted at flat-lot prices. Moraga’s expansive clay and shallow bedrock mean many detached ADUs need piers and grade beams. A builder who assumes slab-on-grade is setting you up for a budget blowout after design starts.
- Design review surprises. The town reviews hillside projects for slope stability, view impacts, and erosion control. Plans that skip geotechnical triggers get sent back for revision, stalling permits for months.
- Fabrication lead times ignored. Custom millwork, architectural glass, and specialty windows take time to build. Schedule them late and the ADU calendar runs long. We order long-lead items early and lock the price before fabrication starts.
- Drainage treated as an afterthought. Winter rains on steep Moraga slopes erode unprotected soil and test foundation waterproofing. Retrofitting drainage after the fact costs more than designing it right from the start.
Pricing for ADU Builders in Moraga, CA
A detached ADU in Moraga typically runs $280,000 to $520,000. A Garage Conversion Contractor in Moraga typically charges $120,000 to $220,000 when the existing structure is sound. These ranges reflect real Moraga site conditions: pier-and-grade-beam foundations where soils demand them, drainage and erosion control on slopes, custom finishes, and the long-lead items that drive the schedule. Design and engineering typically add $15,000 to $35,000. Site work, retaining walls, and utility connections can add more depending on your lot. We give a written line-item price before any work starts, and that number doesn’t change at the door. Call (707) 760-0502 for a free estimate, and we’ll walk the site together before we quote anything.
We Also Serve Cities Near Moraga
In addition to our work across ADU Builders in Moraga, we serve homeowners in Orinda, Oakland, Emeryville, and San Leandro. Each city has its own planning rules and site conditions, and we bring the same written-price, written-guarantee approach to every project. If your lot is in a neighboring community, call (707) 760-0502 and we’ll tell you what applies to your specific site.
Serving Moraga, CA - Our Local Coverage Area
We’re based in the Moraga 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 About ADU Builders in Moraga
Because Moraga’s hillside lots sit on expansive clay and shallow bedrock, and a foundation designed for flat clay doesn’t work on a slope. A geotechnical report tells us what’s under your lot and what foundation system will hold. Without it, a quote is a guess. We order the report before we price the foundation, so your written price reflects actual soil conditions, not an assumption. Call (707) 760-0502 to schedule a site walk and soil review for your lot.
Design review in Moraga evaluates slope stability, view impacts, and neighborhood compatibility. Custom glass and millwork are looked at closely for exterior appearance, but the real delays come from missing geotechnical and drainage details. We submit plans with slope analysis, erosion control, window schedules, and material samples from the start. That proactive packet gets projects approved faster. Call (707) 760-0502 and we’ll explain what your specific project needs to clear review.
Materials. Custom millwork, architectural glass, and specialty window fabrication set the calendar on high-end Moraga ADUs. Framing and site work typically take weeks; custom fabrication can take months. That’s why we order long-lead items early and lock the price in writing before fabrication starts. It keeps your project moving and your number fixed. Call (707) 760-0502 for a free estimate that accounts for real lead times.
Sometimes, but not always. Prefab and panelized units from Abodu and Cover work on many slopes, but the foundation still has to match the soil. If your lot has expansive clay or shallow bedrock, you’ll likely need piers and grade beams even for a prefab unit – the foundation logic doesn’t change. We coordinate directly with these manufacturers to match the unit to your geotechnical conditions. Call (707) 760-0502 and we’ll review your lot before you commit to a prefab design.
We quote the long-lead items early and lock vendor pricing before fabrication begins. That means selecting millwork, glass, and finishes during design, not after framing. The written price you receive includes those materials at locked costs. If a vendor raises prices later, that’s our problem, not yours. The 365-Day Done Right Promise backs the whole build. Call (707) 760-0502 to get a written price for your Moraga ADU.
Written by Russ Delmar, Owner at Lodgewick ADU San Francisco, serving Moraga since 2010.
