Free written scope consultation - allowances, timeline, and change-order rules on paper before a single trade is scheduled
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AfterFast, Reliable Home Additions & ADU Across Pomona
Home additions in Pomona run about $45,000 to $130,000 for a room addition, while a full ADU construction project typically falls between $90,000 and $220,000. Those numbers reflect what we actually see on signed contracts in the 91767, 91768, and 91766 ZIP codes, not a national average pulled from a website. If you’re planning an addition off Garey Avenue or converting a garage in the Phillips Ranch area, we’ll give you a written line-item quote with allowances spelled out before any work begins through our Roofing in Pomona and construction services. Call (877) 610-1318 and Tom or one of his sons will talk you through what’s realistic for your lot. Pomona’s soil and seismic conditions change what “standard” means here, and we build accordingly.
Why Barrett & Sons Construction Is Pomona’s Preferred Home Additions & ADU Company
Tom Barrett started this company in 1998, and his sons run the crews on most Pomona jobs. That’s not a marketing line; it’s why calls get answered by a person who actually knows what happened on your street last week. We’ve pulled permits and passed inspections on additions throughout Pomona, from the tree-lined blocks near Lincoln Park to the postwar tract homes east of Reservoir Street and the newer subdivisions off Chino Hills Parkway. Homeowners in Pomona keep calling us back because the price on the contract matches the price on the final invoice. Every scope, every allowance, every change order arrives in writing before a single nail moves. If something isn’t right, Tom comes back. That’s the 90-Day Done Right Promise, written on every contract.
We’re not a franchise dispatching strangers from three counties away. The Barrett & Sons name goes on the truck, and background-checked crew members who carry that name show up in uniform. Our Home Additions & ADU team knows Pomona’s permitting office, its inspectors, and its soil reports. That local familiarity is why we don’t get surprised by a Pomona fault line setback requirement or a clay soil foundation revision halfway through framing. We planned for it before we dug.
Our Home Additions & ADU Services in Pomona
ADU Design & Permitting
Building an ADU in Pomona means navigating California’s statewide ADU laws plus Pomona’s specific zoning overlays, especially in areas where the Pomona fault trace runs through or near a parcel. We handle the design drawings, the soil report coordination, and every permit application. Inspections get signed, because the inspector works for you, not for me. That’s how we like it.
Garage Conversion ADU
Pomona’s 1940s through 1960s slab-on-grade tract homes make garage conversions one of the most popular ways to add living space without touching the main structure. A garage conversion in Pomona typically runs $30,000 to $80,000. The real work is in the details: anchoring to a slab that’s already cracked from expansive clay, bringing the electrical panel up to code, and properly waterproofing a structure that was never designed to be lived in. We’ve done enough of these in the 91767 ZIP to know exactly what the inspector will flag before we start.
New Detached ADU
A new detached ADU in Pomona usually starts around $90,000 and runs up to $220,000 depending on size, finishes, and site work. The foundation is the biggest variable here. Pomona sits on an alluvial fan at the base of the San Gabriels, and the clay soil shrinks and swells with moisture. We over-engineer footings and slab reinforcement so your ADU doesn’t move with the seasons. It costs a bit more up front and saves tens of thousands in structural repairs later.
Junior ADU & Interior Conversion
A junior ADU, often a converted primary suite or a carved-out section of an existing home, can be the most cost-effective permitted unit in Pomona. Homeowners in neighborhoods like Lincoln Park with pre-1920 Craftsmans and Victorians need period-sensitive interior conversions, and those fall under additional historic district scrutiny. We’ve handled those. The paperwork is heavier, and we don’t cut corners on it.
If your addition plans touch the existing footprint, we also handle Kitchen Remodeling in Pomona and Bathroom Remodeling in Pomona so the new space matches the rooms you already live in.
What happens when you call
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A real person answersNo phone trees - you reach a local pro.
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You get an upfront price rangeHonest numbers before anyone is dispatched.
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A background-checked tech heads outLicensed & insured, dispatched right away.
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You approve before work beginsNothing starts until you say go.
Trusted Brands We Service in Pomona
We install Windows & Doors - Pomona solutions from Simonton, Ply Gem, and PGT on additions and ADUs. These are brands you can look up, with published performance ratings and warranties that mean something. Pomona’s position at the eastern pinch point of the San Gabriel Valley means Santa Ana winds can hit sustained gusts of 50 to 60 mph in the fall. We spec window and door packages rated for that wind load, not whatever the supply house has in stock. Our Pomona customers get parts without a two-week wait because we already know what this market demands.
Common Home Additions & ADU Problems We See in Pomona Homes
- Slab heave and foundation cracking from expansive clay soil. The Pomona fault zone runs through the city, and the surrounding clay soil shrinks dramatically in dry spells and swells when the rains come. We see cracked slabs and shifted footings on 1950s and 1960s tract homes routinely during addition planning.
- Cripple wall and anchor bolt deficiencies flagged during escrow. Home inspectors in Pomona routinely flag 1950s-60s homes for missing or undersized anchor bolts. Any significant addition or ADU project needs a seismic retrofit line item to pass inspection, and contractors who don’t bring that up early lose credibility fast.
- Stucco delamination and moisture intrusion on original wood-frame construction. The postwar stucco-over-wood-frame stock across the 91766 and 91767 ZIP codes is now 60 to 80 years old. When we tie an addition into an exterior wall, we frequently strip back stucco and find rotted sheathing behind it that was never visible from outside.
- Undersized electrical panels on mid-century homes. Most Pomona homes built before 1970 have 100-amp panels, which won’t carry a new ADU’s electrical load plus the main house. We include panel upgrades in our written scope up front, because an allowance that isn’t on paper is a surprise waiting for a date.
Pricing for Home Additions & ADU in Pomona, CA
A room addition in Pomona runs $45,000 to $130,000. Detached ADU construction lands between $90,000 and $220,000, and a garage conversion typically costs $30,000 to $80,000. What moves those numbers: foundation work on expansive clay, seismic retrofit requirements on older slabs, the size and finish level of your kitchen or bath inside the new space, and whether you’re adding a second story. A second-story addition above a 1950s slab-on-grade home costs more per square foot because the existing foundation often needs reinforcement. We give you a written line-item quote with every allowance itemized. Before any change happens, you get a written change order with the new price. Call (877) 610-1318 for a free estimate on your Pomona project.
We Also Serve Cities Near Pomona
Barrett & Sons Construction serves the Pomona area and the surrounding communities. If you’re planning a project in San Dimas, La Verne, Charter Oak, or Diamond Bar, our Home Additions & ADU in Pomona team covers those cities too. The same written change orders, the same permits-pulled standard, and the same 90-Day Done Right Promise apply everywhere we work.
Serving Pomona, CA - Our Local Coverage Area
We’re based in the Pomona 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 - Home Additions & ADU in Pomona
A room addition in Pomona typically costs $45,000 to $130,000 depending on size, foundation requirements, and finishes. A detached ADU runs $90,000 to $220,000, and a garage conversion falls between $30,000 and $80,000. Call (877) 610-1318 and we’ll give you a written, line-item quote specific to your lot and your soil conditions.
Most Pomona lots zoned for single-family residential qualify for at least one ADU or JADU under California state law, but lot size, setbacks, and the Pomona fault trace can change what’s buildable. We review your parcel’s specifics and tell you straight what fits. Give us a call at (877) 610-1318 and we’ll look it up while you’re on the phone.
A garage conversion typically takes 3 to 5 months in Pomona, a room addition runs 4 to 7 months, and a new detached ADU can take 6 to 10 months depending on permitting and site work. Pomona’s historic district requirements, where they apply, add paperwork time. We give you a written schedule with your estimate, and we stick to it unless weather or inspection backlogs intervene.
Not without a written change order signed by you first. Every scope, every allowance, every price change arrives on paper before work proceeds. If you decide to upgrade cabinets or add a window after framing starts, you’ll see the exact cost difference in writing before we buy anything. Call (877) 610-1318 and ask Tom about how we handle allowances.
Yes, permits are pulled and inspections are signed on every eligible job, no exceptions. The permit inspector works for you, not for me. We’ve had Pomona homeowners tell us their last contractor said permits were optional. They’re not, and we won’t pretend otherwise.
Yes. Every Barrett & Sons Construction project in Pomona is backed by the written 90-Day Done Right Promise. If something isn’t done right, Tom comes back and makes it right with one call. That’s on every contract, not buried in fine print.
Contact Barrett & Sons Construction in Pomona
If you’re thinking about an addition, ADU, or garage conversion in Pomona, call (877) 610-1318 for a free estimate. You’ll get a real person on the line, a straight answer about your lot, and a written quote with no surprises. Tom Barrett lives close enough to care, and his sons will be the ones swinging the hammers. Serving Pomona and the surrounding communities with the same name on the truck since 1998.
Written by Tom Barrett, Owner at Barrett & Sons Construction, serving Pomona and the surrounding communities since 1998.