A quiet residential street with a new ADU behind one of the homes
Highland, CA

ADU Company in Highland - Plans, Permits & Build, One Fixed Price

We handle the design, the engineering, and the city permit, then build it. One contract, one crew, one accountable point of contact. Free feasibility check on your lot before you commit.

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The bedroom inside a new ADU
The bathroom inside a new ADU
A small deck outside a new ADU
The living room inside a new ADU
A new two-story ADU over a garage
A new sunroom addition with three walls of windows
A kitchenette inside a converted garage
A second-story addition that matches the existing roofline
Every project starts with

A free site visit, a check of what your lot allows and a written, line-item price.

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ADU Company in Highland, CA

Fielding ADU Builders handles ADU construction, garage conversions, and room additions in Highland, CA. The work here runs into a particular set of conditions: older slab homes on compact lots, a warm inland climate that punishes cheap materials, and a city planning process that asks for real drawings before anything gets approved. Whether you’re adding a backyard unit off Baseline or converting an attached garage on a 1970s ranch, the job starts with a written price and ends with a one-year written guarantee. Call (361) 315-4177 to talk it through.

Call (361) 315-4177

Why Highland Homes Are Different

A new modern ADU with wood cladding

Highland’s housing stock is mostly mid-century single-family homes, and a lot of them were built before the current energy code existed. That matters for two reasons. First, the original electrical panels and subpanels are often undersized for an ADU or a converted garage with its own kitchenette, so part of the scope frequently includes a service upgrade. Second, the slab foundations on these older homes are generally sound, but they have settled, which means tying a new room addition into the existing roofline takes more care than it does on a newer build.

The climate works in your favor and against it. Highland gets hot, dry summers and mild winters, which means a well-built ADU doesn’t fight moisture the way a coastal unit would. But the sun exposure is real. We spec roofing and siding products that hold up under sustained UV rather than the cheapest available trim, and we size the mini-split or HVAC rough-in for the actual summer highs along the East Highland bench. Lots in the older neighborhoods east of the 210 tend to be deeper than they are wide, which shapes where a rear ADU can sit and still leave you a usable yard.

Our Main Highland Services

Most Highland homeowners call us about one of three things: adding square footage to the existing house, converting a garage into living space, or building a detached ADU in the back. Each one has its own page with pricing, timelines, and the permit realities specific to Highland.

Room Addition Contractor in Highland

A room addition here usually means a master suite bump-out or a family room extension, and the biggest variable is how the new roofline ties into the old one. Highland’s mid-century ranches have low slopes, so we typically match the existing pitch and carry the fascia line straight through rather than leaving a visible seam. The foundation work is straightforward on most flat lots, but a few hillside properties east of Webster need taller stem walls and extra drainage. The written price covers all of it before we start. See the full scope here: Room Addition Contractor in Highland.

Room Addition Contractor in Highland

Garage Conversion Contractor in Highland

Garage conversions are popular in Highland because the attached two-car garages on 1960s and 1970s homes are often underused, and the footprint is already there. The work involves turning a slab-on-grade garage into conditioned space: insulation in the walls and ceiling, drywall, flooring, and a proper electrical run for heat and light. Highland’s building department wants a clear change-of-use permit and a plan showing how the new room meets egress and ventilation requirements. We handle the drawings and the whole build: Garage Conversion Contractor in Highland.

Garage Conversion Contractor in Highland

ADU Builders in Highland

Detached ADUs in Highland fall into two camps: conventional stick-built units and prefab platforms that arrive in modules and get set on a foundation. Most Highland lots can take a one-bedroom or two-bedroom unit in the rear yard without a variance, but setback rules shift depending on whether your lot is standard, corner, or flag-shaped. We work with Abodu, Cover, Dvele, and Mighty Buildings where the prefab route fits the budget, and we stick-build with James Hardie siding when the lot or the design calls for it. Full details: ADU Builders in Highland.

ADU Builders in Highland
Need help today?Fast, friendly service and a no-obligation free estimate.

Call (361) 315-4177

What happens when you call

  1. 1
    A real person answersNo phone trees - you reach a local pro.
  2. 2
    You get an upfront price rangeHonest numbers before anyone is dispatched.
  3. 3
    A background-checked tech heads outLicensed & insured, dispatched right away.
  4. 4
    You approve before work beginsNothing starts until you say go.

Brands We Service in Highland

Fielding ADU Builders works with several prefab and modular ADU platforms as well as conventional materials. Depending on the project, we install units from Abodu, Cover, and Dvele, and we build conventionally with James Hardie siding and Tuff Shed-style structures. See our brands for the full list and what each one fits best.

Pricing for ADU Company in Highland, CA

Service Typical range in Highland
Garage conversion (full unit) $80,000 – $120,000
Garage conversion (basic finish) $60,000 – $85,000
Detached ADU (prefab, 1-bed) $120,000 – $180,000
Detached ADU (prefab, 2-bed) $180,000 – $260,000
Detached ADU (conventional build) $200,000 – $350,000
Room addition (200 – 400 sq ft) $60,000 – $140,000
Room addition (400 – 800 sq ft) $120,000 – $240,000
Electrical service upgrade (if needed) $3,000 – $6,000
Foundation work (new stem wall) $4,000 – $10,000
Permit fees and plan drawings $2,500 – $7,000

Prices in Highland move up when the lot is tight and access for equipment is limited, or when the original electrical panel needs to be brought up to current code before an ADU can be fed. The price we put in writing before any work starts is the price you pay at the end. No change orders, no surprises at the final invoice.

Neighborhoods We Serve in Highland

We work across the whole of Highland, from the older streets west of the 210 to the newer tracts along the east side of town. Crews are local to the Inland Empire and scheduled through our Riverside-San Bernardino office, so response time for estimates is usually within a few days.

  • East Highlands
  • Highland Village
  • The bench neighborhoods east of Webster
  • Tracts along Baseline and Greenspot
  • Areas bordering San Manuel Reservation

Service Area – Cities Near Highland

If you’re just outside Highland, we also cover the surrounding Inland Empire cities. We work in San Bernardino, CA, Loma Linda, CA, Redlands, CA, and Mentone, CA. Give us a call and we’ll confirm coverage for your exact street and lot.

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 Company in Highland

A compact kitchen inside a new ADU

Ready to get started? Free estimates · Free in-home estimates response in Highland
Call (361) 315-4177

What happens when you call

  1. 1
    A real person answersNo phone trees - talk to a local adu pro.
  2. 2
    You get an upfront price rangeHonest numbers before anyone is dispatched. No surprises.
  3. 3
    We come out and measureLicensed & insured, at a time that suits you - the visit and the quote are both free.
  4. 4
    You get the price in writingLine-itemed, yours to keep, and nothing starts until you say go.

What Highland Customers Say

★★★★★ 4.9 from 8+ reviews

"Insulation, drywall, and finishes were all well done. Feels like part of the house."

- Pete O.

"Built a detached ADU behind our house. The builder is a veteran and runs the site like a platoon: schedule posted, crew on time, everything labeled. Finished within a few days of the date."

- Ken W.

"Room addition over the back patio. Framing is square, windows are tight, and the roofline matches."

- Danny L.

How It Works in Highland

Getting your adu handled is simple and fast.

1

Call or Request a Free Estimate

Tell us about your adu needs and we provide an upfront, transparent quote - no obligation, no hidden fees.

2

Licensed Technician Dispatched

A background-checked, certified technician arrives in Highland - typically within 30-60 minutes, with parts stocked on the truck.

3

Problem Solved, Guaranteed

We complete the job to your full satisfaction, backed by our warranty and 100% satisfaction guarantee.

More ADU services in Highland

Every build below starts the same way: a free site visit and a written price.

Getting started with Fielding

Every project starts with a conversation and a written price. Here is how to take the first step.

A project lead measuring a backyard ADU site with the homeowner

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