Plant Prefab ADU Builders in San Jose: What to Know First
We’re independent Plant Prefab ADU builders serving San Jose homeowners who need installation, finishing, or repair work on their prefab accessory dwelling units. Most Plant Prefab projects here take 3 to 6 months from foundation to final inspection, depending on lot conditions and the level of finish you’re after. A detached Plant Prefab ADU in San Jose typically lands between $180,000 and $350,000 all-in, including site prep, foundation, utility connections, and interior finish. If you own a Plant Prefab unit or are planning one, call (669) 266-4319 and we’ll give you a written price before any work starts.
This page is for homeowners who already have a Plant Prefab ADU or are actively considering one. As an independent Plant Prefab service provider, we install, complete, and repair these units without being tied to the manufacturer’s sales process. That means we tell you what’s actually true about your unit, not what a brochure says. Russ Delmar and our crew have been working on prefab ADUs across San Jose since before most homeowners even knew the term.
How Plant Prefab Products Fail – and How We Fix Them
- Foundation interface gaps on the LivingHome series. Plant Prefab’s LivingHome line ships in modules that sit on a prepared foundation, and we’ve seen repeated issues where the mating surface between module and foundation wasn’t shimmed correctly during delivery. This shows up as hairline cracks along interior wall seams within the first 18 months, especially in San Jose’s clay-heavy soil zones like Almaden Valley. We re-level the structure with precision shims and seal the interior seams so they stay closed.
- Roof membrane stress at module seams on the YB series. The YB (yard barn) models have a clean modern profile, but the roof membrane at the junction between modules takes real stress during transport and thermal cycling. San Jose’s summer heat spikes hit 90s regularly, and that expansion-contraction cycle can separate membrane laps. We inspect every seam, re-weld or re-tape them as needed, and flash the edges properly before any finish work starts.
- Electrical rough-in variances on custom LivingHome builds. Plant Prefab does factory electrical rough-in, but we regularly find outlet placements that don’t match the approved San Jose permit drawings. The city’s inspectors care about this, and so do we. We pull the panels, re-route what needs re-routing per the stamped plan, and keep your electrical permit moving without a stop-work order.
- Bathroom waterproofing breakdowns in the LivingHome 10 and 12 models. Factory-installed shower pans and wall boards occasionally fail at the corner joints within the first two years. The cause is usually differential settling between the module chassis and the site-built bathroom floor. We remove the affected tile, re-waterproof properly with Schluter or equal, and re-set the tile. The fix holds because we address the floor plane first.
- HVAC duct disconnects in the Plant Prefab series with roof-mounted units. When the module rides down the highway, duct connections can separate in the ceiling cavity. Homeowners notice one room stays cold in summer. We pull the ceiling access panels, reconnect and brace the ducts, and test airflow before we close things up. This is a San Jose-specific reality for any prefab that comes up from Southern California on a flatbed.
Our Plant Prefab ADU Builders Process
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Call and talk to a person. A live human answers (669) 266-4319. Tell us what’s going on with your Plant Prefab unit, and we’ll set a site visit window that actually works for you.
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Site visit and condition report. We walk the property, inspect the unit from foundation to roof, and write down what we find. You get photos and a plain-English summary of what’s wrong and what’s normal.
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Written price, fixed. We give you a line-item written price for the work before anything starts. That number doesn’t change unless you ask us to add scope. No door-price surprises. Ever.
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Parts decision: OEM vs quality aftermarket. For Plant Prefab components, we weigh factory parts against proven aftermarket equivalents. If the factory part has a known failure pattern, we’ll recommend the better aftermarket option and explain why. You decide with full information.
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The build and the test. We do the work, keep the site clean each day, and then test everything: level, plumbing pressure, electrical load, drainage, waterproofing, and fit-and-finish details.
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Written guarantee and follow-up. Before we leave, you get our 365-Day Done Right Promise in writing. If something isn’t right within that year, we come back. That’s not a slogan. It’s in your paperwork.
What Plant Prefab ADU Builders Costs in San Jose

Here’s the honest picture on pricing in San Jose, where labor and permit costs run higher than the national average:
- Studio Plant Prefab ADU (under 500 sq ft): $150,000 to $220,000 all-in, depending on foundation depth and utility runs.
- One-bedroom LivingHome ADU (500-750 sq ft): $220,000 to $300,000 with mid-grade finishes.
- Two-bedroom LivingHome or custom Plant Prefab (750-1,200 sq ft): $300,000 to $425,000, with kitchen and bath finish level swinging the number the most.
- Garage conversion using Plant Prefab modules: $130,000 to $200,000 if the existing slab and framing can be reused.
- Repair or re-leveling work on an existing Plant Prefab unit: $8,000 to $35,000 depending on what’s failing and how much finish demolition is involved.
What moves the price in San Jose: soil conditions, set-back requirements, permit fees, utility trenching distance, and the finish level you choose for flooring, tile, cabinets, and fixtures. We give written prices before work starts, so you’ll know your number before you’re committed. Call (669) 266-4319 for a free estimate.
Why San Jose Homeowners Call Lodgewick ADU San Jose for Plant Prefab Work
Most of our Plant Prefab clients in San Jose come to us after a previous contractor left them holding a half-finished build or a stack of unanswered questions. We run this company under The Kingswell Guarantee, which means four things written into every job: a written price before work begins, a defined arrival window, a clean job site every day, and a written guarantee on every project. If the work fails within 365 days, we come back and fix it. That’s the 365-Day Done Right Promise, and it’s not a verbal assurance. It’s a written guarantee delivered before your project starts. Russ Delmar has been building ADUs across San Jose for over a decade, and he’ll be the first to tell you what a previous contractor promised him versus what we can actually deliver. Tell me what you were promised before, and I’ll tell you what we can actually deliver. Our crews also work regularly with Abodu, Cover, and Dvele units, so when we look at your Plant Prefab, we know how it compares structurally and operationally to the other prefab ADUs in this market.
Frequently Asked Questions

Yes. As an independent Plant Prefab service provider, we can perform diagnostic and repair work without voiding your manufacturer’s coverage, and we’ll document everything in a way that supports any warranty claim you file. The issues we find are often covered by Plant Prefab’s structural warranty, but the manufacturer may still require a local licensed contractor to do the physical work. That’s where we come in. Call (669) 266-4319 to discuss your specific warranty situation.
Plumbing, electrical, and finish materials are available locally within days from San Jose suppliers. Plant Prefab-specific components like custom millwork panels or specialized window assemblies may take 2 to 6 weeks depending on the manufacturer’s production queue. We plan around these lead times and can often install temporary fixtures so the unit stays usable while factory parts ship. Call (669) 266-4319 and we’ll tell you what your specific unit needs.
Repair is usually the right call if the structure is sound and the issues are in finishes, waterproofing, or mechanical systems. Replacement makes sense when foundation movement has compromised the module chassis itself, or when repair costs exceed 60% of the unit’s value. Most Plant Prefab ADUs in San Jose have a 50-year design life, so the math usually favors fixing what’s there. Call (669) 266-4319 for an honest assessment.
No. We give you a written price before any work starts, and that number is the number. The only way the price changes is if you ask us to add something that wasn’t in the original scope, and then we’ll put that addition in writing before we do it. No door-price changes. Ever. That’s the Kingswell Guarantee, and it’s been our operating rule since 2010.
Yes. We handle the San Jose building permit process, including plan review, inspections, and the final sign-off. We pull permits before work starts and we don’t leave until the unit passes its final inspection. Call (669) 266-4319 to schedule your free estimate.
Written by Russ Delmar, Owner, Lodgewick ADU San Jose at Lodgewick ADU San Jose, serving San Jose and nearby areas.


