ADU Builders in Pomona — Design, Permits and Build Under One Contract

Fast, Reliable ADU Builders Across Pomona

If you own a home in Pomona and you’re weighing an ADU, you’re probably already running into the same thing every local homeowner does: your lot can handle it, but your house can’t. Not yet, anyway. Holloway ADU Builders works across Pomona every week, and most projects we take on in 91766, 91767, 91768, and 91769 start the same way: we open the panel, separate the service, and then we frame. We know Pomona’s housing stock, its back-alley garages, and its permitting quirks. Call (855) 617-6356 to schedule a free estimate, and we’ll walk your lot with you before you commit to anything.

Call (855) 617-6356

Why Holloway ADU Builders Is Pomona’s Preferred ADU Builders Company

Pomona homeowners don’t need a contractor who treats an ADU like a side job. They need someone who has already untangled the electrical and permitting knots that define this city’s older tract neighborhoods. Our team, led by Neil Trescott, spends more time in Pomona than most local general contractors, and the pattern is consistent: a homeowner wants a backyard ADU, a garage conversion, or a junior unit, and the first conversation always lands on the service panel before the floor plan.

We’re known in Pomona for doing the unglamorous work first: separating shared meters, upgrading 100-amp panels to 200-amp, and pulling permits for ADUs that were never legalized. Homeowners call us because we don’t pitch a structure that the lot can’t support and we don’t pretend a 1950s panel will carry a new ADU’s load. When we give a Pomona homeowner a quote, it includes the electrical reality, not just the square footage.

We work with ADU Builders approaches across the spectrum: prefab, modular, and site-built. That matters in Pomona because some alleys and setback lines favor a particular method, and we’ll tell you which one makes sense for your lot rather than pushing one brand.

ADU Design in Pomona

ADU Design in Pomona almost never starts with choosing cabinets. It starts with a survey of what the existing property can actually carry: lot lines, alley access, roof drainage, and electrical service. A typical ADU Design engagement in Pomona runs $4,000 to $9,000 for drawings, site review, and the structural and electrical scoping that older tract homes require. That number climbs when we’re legalizing an unpermitted garage conversion, because the design work has to reconcile what’s there with what the city will sign off on.

Panel-First Design Scoping

We’ve walked dozens of Pomona ADU projects where the design looked simple on paper. Then we checked the panel. If you’re in a 1950s home on a 100-amp service, the design phase has to account for a 200-amp upgrade and a separate meter before a single wall goes up. Our drawings reflect that sequence.

Alley Access and Setbacks

East-side Pomona lots often have alley access behind the property. That changes where a detached ADU can sit, how materials get delivered, and how the entry works. We draw to the actual access, not a generic template.

Backyard ADU in Pomona

A Backyard ADU in Pomona is one of the few places in Southern California where a detached unit on a large, flat lot makes more sense than an attached conversion. Pomona’s postwar tracts in 91767 and 91768 sit on lots big enough to handle a separate structure, and those back-alley garages are natural candidates. A detached Backyard ADU in Pomona typically lands between $180,000 and $320,000 for site-built construction, with prefab and modular options running lower depending on the manufacturer and site prep.

Garage Conversion vs. New Detached Unit

If your Pomona garage was built in the 1950s and never permitted as living space, a conversion can be the more affordable path, often $120,000 to $200,000. But the electrical must be separated and metered correctly, or the city won’t sign off. We handle that before framing.

Tuff Shed Conversion Route

For Pomona homeowners on a tighter budget, we’ll sometimes recommend a Tuff Shed conversion approach. That can bring a Backyard ADU under $100,000 in the right lot conditions, though it still requires the same panel and meter work as any other ADU.

Trusted Brands We Service in Pomona

Holloway ADU Builders is brand-agnostic, which means we’re not married to any single ADU manufacturer. In Pomona we work with Cover, Dvele in Pomona, and Boxabl, among others, and we’ll help you compare them honestly based on your lot, your timeline, and your budget. We stock common parts and materials for these systems locally, so Pomona customers aren’t waiting on weeks-long supplier shipments for basic components. From Abodu to Tuff Shed conversions, we’ve navigated every type of ADU project, and in Pomona that experience matters because the existing structure often dictates which brand actually fits.

Common ADU Builders Problems We See in Pomona Homes

• Shared electrical service on back-alley garages. Many Pomona garages off the east-side alleys pull power from the main house. Before an ADU can be permitted there, the service must be separated and a meter established. We do this first, every time.
• Cloth-wrapped wiring and undersized framing. Open a wall on a 1950s Pomona tract home and you may find cloth-sheathed cable and 2×4 framing that was never built for a second unit. We inspect before we quote, so those discoveries don’t become change orders.
• Unpermitted garage conversions. Pomona has a lot of garages that were converted years ago without permits. Legalizing one as an ADU requires bringing the structure up to current code. That’s not a dealbreaker, but it has to be part of the plan from day one.
• Flat and low-slope garage roofs with failed drainage. Pomona’s hot summers and Santa Ana winds bake roofing materials. Then winter rains arrive. A flat roof with poor flashing fails fast. We re-detail drainage and ventilation before we do interior work.

Pricing for ADU Builders in Pomona, CA

Local Conditions That Shape Pomona ADU Work

Pomona’s postwar tract housing across 91766 through 91768 sits on large, flat lots with alley access. That’s a real advantage for detached ADUs, because neighboring cities like Claremont and La Verne often have tighter lots that force attached conversions. But most Pomona homes are on 1950s-era 100-amp service, so the ADU conversation almost always starts with a panel and service upgrade. This panel-first sequence is rarely the case in cities with newer housing stock. It’s the single most common first step we handle in Pomona.

We also deal with Pomona’s climate. Inland Pomona sits at the base of the San Gabriel foothills with hot, dry summers and Santa Ana wind events. ADUs here need proper roof ventilation and window shading. And the flat or low-slope garage roofs common across the city require careful drainage detailing for winter rains. Skip that step, and you’ll have waterproofing failure within the first season.

One field example: on a 1953 slab-on-grade stucco tract home off the east-side alleys near Phillips Mansion, our crew opened the detached back garage for a conversion and found cloth-wrapped wiring, a shared service drop with the main house, and a low-slope roof with failed flashing. We pulled the panel and separated the meter first, replaced the roof drainage detailing with new flashing and vents, then framed the ADU interior. The client approved every line-item surprise in writing before we touched the framing. That’s how we work across Pomona, and it’s why our projects don’t spiral.

We Also Serve Cities Near Pomona

Holloway ADU Builders works throughout the Pomona Valley and nearby Inland Empire cities. In addition to Pomona, you’ll find our teams in La Verne, Claremont, Montclair, and Los Serranos. If you’re a homeowner in one of those cities exploring an ADU, call us at (855) 617-6356 or reach out through our ADU Builders page to learn more.

FAQs About ADU Builders in Pomona