ADU Builders in San Bernardino - Design, Permits and Build Under One Contract

Fast, Reliable ADU Builders Across San Bernardino

Building an accessory dwelling unit in San Bernardino means adding a second home to your lot, whether it’s a detached backyard unit, a garage conversion, or a junior ADU tucked into your existing floor plan. We know this city’s post-war housing stock, its heat, and its specific permitting hurdles. If you’re weighing an ADU on a Del Rosa lot or a Verdemont hillside parcel, call (254) 602-5618 and we’ll walk you through what’s actually involved, in plain terms, before you commit to anything.

Call (254) 602-5618

Most San Bernardino homeowners we meet want one thing first: a real number in writing. We give you that. No vague ballpark that drifts upward once the permit is pulled. The Kingswell Guarantee means a written price before any work starts, a defined arrival window, and a written guarantee on the finished build. Russ Delmar leads our team here, and he’ll be the one making sure that guarantee holds.

Why Lodgewick ADU Builders Is San Bernardino’s Preferred ADU Builders Company

San Bernardino homeowners have told us stories about contractors who quoted one price, then showed up with a change order before the slab was poured. We built this company in 2010 inside the Kingswell family of home-service businesses specifically to stop that pattern. Every project we take in San Bernardino starts with a written price and ends with a written guarantee. If the work isn’t right within 365 days, we come back and make it right. That’s the 365-Day Done Right Promise, and it’s in writing on every project we do.

Our crews are background-checked and uniformed, so when someone pulls up to your San Bernardino home, you know exactly who they are. We answer our phones with a live person around the clock. No voicemail loop when you have a question about your ADU’s progress or the guarantee. And because we coordinate from our Inland Empire office, we know the permitting offices, the inspectors, and the utility requirements that San Bernardino projects run into. Russ doesn’t hand your build off to a rotating cast of subcontractors and disappear. You’ll know who’s accountable.

ADU Contractor in San Bernardino

Hiring an ADU Contractor in San Bernardino means bringing in a team that handles the whole build, from the first site walk to the final inspection. You need a contractor when the project involves structural changes, new foundations, utility connections, or any work that requires a permit, which is nearly every ADU in this city. A full-service ADU build here typically runs $180,000 to $420,000 depending on whether you’re doing a prefab studio or a custom two-bedroom detached unit. A garage conversion runs $90,000 to $220,000. Those are real numbers for this market, and we’ll put yours in writing.

Site Preparation and Foundation

San Bernardino’s older lots hide surprises. Before we quote a detached ADU, we check the soil, the existing lateral connections, and the grading on your parcel. On a 1956 wood-frame ranch in the Del Rosa neighborhood, our crew opened the rear wall for a garage-conversion ADU and found cloth-wrapped wiring, a rotted top plate, and a failed shower pan in the old garage slab. We wrote the lateral capacity review and the mini-split heat-load sizing into the contract as allowances before demo, then priced the panel upgrade and framing repairs in writing before touching anything. That’s how a contractor should handle an older San Bernardino home.

Permits and Utility Capacity

San Bernardino’s 2012 municipal bankruptcy left many older residential water and sewer laterals undersized. When you add an ADU with its own bathroom, kitchen, and laundry, the city’s utility capacity review can flag your lateral as insufficient. That triggers an upgrade cost, often $6,000 to $18,000 depending on the line and the distance to the main. We include this review in every quote for older blocks. Out-of-area contractors routinely miss it until the inspector shows up, and then the homeowner eats a surprise bill. We don’t do that to people.

ADU Design in San Bernardino

ADU Design in San Bernardino has to account for three things most coastal designers never think about: 108-degree basin heat, Santa Ana winds, and fire-zone requirements in the northern foothills. We design every ADU around a mechanical cooling load sized for San Bernardino’s actual summertime heat gain, not an average Inland Empire number. Design and engineering for a custom ADU here typically runs $8,000 to $25,000 depending on complexity. Prefab units from Abodu or Cover often reduce design costs significantly since the engineering is already done.

Fire-Zone Design Upgrades

If your parcel sits in the Verdemont district or anywhere near the San Bernardino National Forest boundary, your ADU likely falls within a Very High Fire Hazard Severity Zone. That changes the design before we draw a single line. Ember-resistant vents, Class A roofing, and non-combustible cladding become mandatory, and they add $15,000 to $40,000 compared to a flatland ADU just a mile or two south. We tell you this in the first conversation. It’s not an upsell. It’s a code requirement, and ignoring it only creates a failed inspection and a longer wait.

Layouts That Work on San Bernardino Lots

San Bernardino’s post-WWII residential grid is built on large lots, commonly 7,000 to 9,000 square feet. That means detached ADUs are physically feasible on a far higher share of parcels here than in denser coastal markets. We design around your lot’s actual shape and setbacks. A 500-square-foot studio ADU fits comfortably behind most San Bernardino ranch homes with room to spare for the required four-foot rear and side setbacks. We use Dvele and Mighty Buildings systems when speed and precision matter, and stick-frame construction when your lot or vision calls for it.

Trusted Brands We Service in San Bernardino

We work hands-on with established ADU manufacturers and keep current on their specifications, lead times, and installation requirements so San Bernardino customers don’t have to become product researchers. Abodu and Cover prefab units are solid choices for flatland lots with straightforward access. Dvele offers high-performance units that work well in fire-zone parcels because of their self-sufficient power systems and ignition-resistant detailing. We don’t push one brand over another. We match the unit to your lot’s constraints, the city’s fire-zone rules where they apply, and your budget. And we handle the parts, the delivery coordination, and the final fit-out so you’re not stuck managing a factory schedule.

Common ADU Builders Problems We See in San Bernardino Homes

• Undersized mini-splits that can’t keep up. San Bernardino sits in a basin that traps heat, regularly logging summer highs of 108 to 112 degrees. A unit sized for average Inland Empire loads will leave your ADU miserable in July. We size for your parcel’s actual heat gain, not a regional average.
• Bankruptcy-era lateral deficiencies. Many older blocks still carry undersized water and sewer laterals from before the city’s 2012 financial collapse. The city’s mandatory utility capacity review flags these, and the upgrade cost appears mid-project if nobody planned for it. We build the review into every quote.
• Cloth-wrapped wiring behind fresh drywall. Homes built in the 1950s and 1960s often still have original electrical systems. Opening walls for an attached ADU or garage conversion frequently triggers a full panel and wiring upgrade once the permit is pulled. We price this as an allowance before demo, never as a surprise change order.
• Fire-zone requirements nobody mentioned. North San Bernardino foothill areas near the national forest boundary fall within Very High Fire Hazard Severity Zones. The cladding, venting, and roofing requirements add real cost. A contractor who doesn’t know the zone boundaries will underbid, then come back asking for more money. We check the fire-zone map before we quote.

Pricing for ADU Builders in San Bernardino, CA

We Also Serve Cities Near San Bernardino

Our ADU Builders serve San Bernardino and the surrounding communities, including Loma Linda, Highland, Rialto, and Colton. If you’re searching for ADU Builders in any of these nearby cities, we’re already familiar with their local permitting differences. The same written-price guarantee and 365-Day Done Right Promise applies. Read more about our work in San Bernardino and then call us for a straight answer on your specific property.

FAQs About ADU Builders in San Bernardino