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 Highland
Building an ADU in Highland means getting the permit path right before you ever pour concrete. Between the City of Highland and San Bernardino County jurisdictions, the wrong assumption can cost you weeks. We scope every Highland project against the specific parcel’s annexation history, soil conditions, and setback rules before we give you a written price. Call (903) 568-7222 and you’ll reach a live person who can talk through your property right now.
Highland homeowners ask us two things on every call: “What will this actually cost?” and “How long until I can rent it out?” We answer both in writing. No verbal ballpark that drifts later. Troy Eastman and our ADU Builders team put the full scope, the brand selections, the permit checklist, and the line-item price on paper before any work starts.
Why Benson ADU Builders Is Highland’s Preferred ADU Builders Company
Highland sits in a tricky jurisdictional pocket. Some parcels answer to the City of Highland, others to San Bernardino County, and a surprising number require sign-off from both depending on when the land was annexed. We’ve pulled permits for ADUs on both sides of that line. That matter-of-fact familiarity with the local process is why Highland homeowners keep referring us to their neighbors along Base Line, Greenspot Road, and Fifth Street.
Troy leads every Highland estimate personally. He’s walked properties near Highland Avenue and Victoria Avenue, and he’ll tell you straight if your garage conversion is a smart JADU candidate or if a detached build makes better sense on your lot. Our technicians arrive in uniform and badge-checked, so you know exactly who’s on your property from day one.
Detached ADU in Highland
A Detached ADU in Highland is a standalone living unit built in your backyard, physically separate from the main house. For most Highland lots running east of the 210, the setback determines everything: how wide the unit can be, where the entrance faces, and whether you need a soil report before foundation design begins. A typical detached ADU in Highland runs $180,000 to $320,000 depending on size, site access, and whether you’re going prefab or site-built.
When a Permit Needs Two Agencies
If your Highland parcel sits in a county pocket, expect both City and County review. That’s not a delay you can design around; it’s a process we schedule for. We build the extra review time into your timeline, so your start date doesn’t become a moving target.
The Upgrade That Saves You Callbacks
Expansive soils run through parts of the San Bernardino Valley floor, and Highland has its share. We’ve torn up foundation plans more than once after a soil report came back reactive. Spending $2,500 to $4,500 on soil testing and mitigation up front is cheaper than redoing a slab after inspection.
JADU in Highland
A JADU – or Junior ADU – in Highland converts part of your existing home, typically a garage or a large bedroom, into an independent unit with its own kitchen and bath. It’s the fastest and least expensive permitted housing you can add to a Highland property, usually landing between $90,000 and $150,000. Homeowners near the East Highlands Ranch area often look at JADUs as rental-ready within four to six months.
Garage Conversions and Setback Reality
Converting a garage means playing by different fire and egress codes than a detached unit. Highland inspectors are specific about it. We bring those requirements into the price up front, not as a surprise change order after demo starts.
Why Some Garages Don’t Qualify
Not every garage in Highland passes for a JADU. If the slab wasn’t poured to living-space depth or your parcel is tied to CC&Rs that block conversions, you need a different route. We’ll tell you during the first walkthrough, before you spend a dollar.
Trusted Brands We Service in Highland
We’re authorized to build with Abodu, Cover, and Dvele, among other prefab systems, and we finish exteriors with James Hardie siding. For Highland’s dry summer heat and occasional Santa Ana-driven wind, James Hardie holds up better than vinyl or wood composite. We keep pricing current for these systems and can walk you through the cost difference between a panelized Dvele unit and a site-built frame while you decide what fits your lot and your budget.
Common ADU Builders Problems We See in Highland Homes
- Skipping the soil report to save money. Highland’s valley-floor soils can be expansive, and a foundation that isn’t designed for it will crack. The report costs a few thousand; the repair costs tens.
- Assuming one set of setback rules applies everywhere. Some Highland neighborhoods have CC&Rs that tighten what the city allows. We pull the recorded documents before we draw the footprint.
- Missing the dual-permit trigger. Parcels caught between City and County review take longer. We map your parcel history first so you’re not surprised by a second plan check.
- Building a garage conversion on a slab that wasn’t poured for living space. Highland inspectors won’t pass it without underpinning or replacement. That’s a $20,000 conversation you want to have before you sign.
Pricing for ADU Builders in Highland, CA
Here’s what we tell Highland homeowners on the first call. A JADU conversion: $90,000 to $150,000. A detached one-bedroom ADU: $180,000 to $240,000. A two-bedroom detached with site-built framing: $260,000 to $320,000. Prefab systems like Cover or Dvele can tighten the build window but run toward the higher end, typically $280,000 to $340,000 installed. What moves the number: soil mitigation, utility trenching distance, foundation type, and whether your parcel needs dual-agency review. You’ll get a written line-item breakdown before you commit to anything. Call (903) 568-7222 and schedule a free estimate.
We Also Serve Cities Near Highland
Our crews serve San Bernardino, Loma Linda, Redlands, and Mentone from the same Inland Empire dispatch network that covers Highland. Same written price process, same 365-Day Done Right Promise, no matter which side of the 210 your parcel sits on.
Serving Highland, CA - Our Local Coverage Area
We’re based in the Highland 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 Highland
Yes, on most parcels. Highland sits on valley-floor soils that can be expansive, and San Bernardino County’s building review expects a geotechnical report before foundation approval. Budget $2,500 to $4,500 for testing and any recommended mitigation. Call (903) 568-7222 if you want us to check your specific parcel before you order one.
Yes, in most cases, but only if the existing slab and roof structure meet residential code. Highland inspectors require proper insulation depth, fire separation, and a dedicated egress path. We’ll tell you during the first site visit if your garage is convertible or if you’re better off with a detached unit.
Expect four to eight weeks for a City of Highland review, and up to twelve if your parcel triggers dual City and County approval. Prefab systems like Abodu or Dvele don’t shorten the permit window, but they can cut four to six weeks off on-site construction. We’ll give you a written timeline before we start.
We’re authorized for Abodu, Cover, Dvele, Mighty Buildings, and several others. We’ll walk you through the trade-offs between panelized and site-built for your specific Highland lot, including how each handles the valley heat and wind. No single-brand pitch; you get options you can research yourself.
Soil mitigation, utility relocation, or a foundation redesign triggered by inspection are the three most common cost changes in Highland. We front-load the soil report, pull utility maps, and verify setback and CC&R status before we price, which keeps your number stable. If something does change, you’ll see it in writing with a revised line-item quote first. Call (903) 568-7222 for an exact quote on your property.
Written by Troy Eastman, Owner at Benson ADU Builders, serving Highland, CA.
