Trusted ADU Site Prep & Utilities for Chino Homeowners
ADU site prep and utilities in Chino typically costs $15,000-$65,000 depending on scope-see our ADU Site Prep & Utilities cost guide for detailed breakdowns-with foundation and grading work starting around $8,000-$18,000 and full utility package upgrades reaching the higher end for properties with aging infrastructure. Most Chino homeowners completing a detached ADU or garage conversion need at least two of the five sub-services we handle: foundation work, electrical panel upgrades, plumbing laterals, gas line extensions, or landscaping and hardscape restoration. Since 2015, Ellery ADU Studio has designed, permitted, and built over 900 ADUs across Southern California, and every site prep and utilities package we’ve quoted has carried a single written price before any work begins, backed by Haven Standard Clause 1.
Chino’s soil conditions vary block by block. Near the Prado Dam basin, we’ve encountered expansive clay that requires deeper footings than the standard 18-inch minimum. In newer developments south of Pine Avenue, the fill soil can settle unevenly if not properly compacted before slab pour. These aren’t theoretical concerns; they’re conditions we’ve documented in permit sets and photo records for properties throughout Chino, our ADU Site Prep & Utilities in Chino Hills, and Eastvale. Our crews are background-checked, uniformed, and state-licensed, and Nadia Ellery reviews every site prep scope personally before it goes to permit. Call (909) 323-1107 to schedule your free estimate. A live person answers 24/7.
What Our ADU Site Prep & Utilities Service Includes
Foundation & Grading
Foundation and grading is the physical preparation of your building pad, including soil compaction, excavation for footings, and the concrete slab or stem wall that your ADU will sit on. In Chino, you’ll need this for any detached ADU or garage conversion where the existing slab is cracked, too thin, or improperly reinforced for residential occupancy. At Ellery ADU Studio, we specify the exact footing depth, rebar schedule, and concrete mix per Chino’s adopted California Building Code amendments, then coordinate the geotechnical report if your lot requires it. Our documented photo record captures every pour and inspection, and the 365-Day Done Right Promise covers foundation settlement or cracking that falls outside normal curing.
Electrical Panel Upgrade
An electrical panel upgrade replaces or expands your existing service to handle the additional load of a full ADU kitchen, laundry, HVAC, and EV-ready outlet. Most Chino homes built before 1990 carry 100-amp panels, which is insufficient for a modern ADU; the city typically requires 200-amp service for detached units over 500 square feet. We handle the load calculation, the Southern California Edison coordination, and the permit pull, all under the same contract as your ADU build. Our electricians are C-10 licensed, and every panel upgrade includes a written line-item quote with no change orders once signed, per Haven Standard Clause 5.
Plumbing Lateral
The plumbing lateral is the underground pipe that connects your ADU’s fixtures to the city sewer main or your existing septic system. In Chino’s older neighborhoods near the downtown corridor, we’ve found clay pipe laterals that have shifted with ground movement and no longer meet current slope requirements. We camera-inspect the existing line, specify the replacement material (typically PVC Schedule 40 or HDPE depending on depth and traffic load), and coordinate with Chino Public Works for any street-to-property-line work. The permit set includes the lateral profile, cleanout locations, and tie-in details, so the inspector sees exactly what we see.
Gas Line Extension
A gas line extension runs a new branch from your existing meter or regulator to serve the ADU’s water heater, furnace, range, or fireplace. Chino’s inland climate means most ADUs here need heating capacity that electric heat pumps struggle to deliver cost-effectively, so gas remains the practical choice for many of our builds. We size the line per the Gas Pipe Sizing Tables in the California Plumbing Code, account for future appliance additions, and pressure-test every installation before SoCalGas signs off. If your existing meter lacks capacity, we handle the meter upgrade application as part of the same scope.
Landscaping & Hardscape
Landscaping and hardscape restoration returns your property to finished condition after construction, including driveway repair, patio reconstruction, irrigation rerouting, and any city-required permeable surface replacement. Chino’s municipal code requires that post-construction lot coverage and drainage patterns match or improve pre-construction conditions, which means we can’t simply pour over everything and call it done. Our landscape crews work from the same permit set as the build team, so the finished grade directs water away from both structures per the site plan we submitted. The photo record documents before, during, and after, and the written warranty covers settlement or drainage issues for 365 days.
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.
Brands We Service for ADU Site Prep & Utilities
We specify and coordinate prefab and modular systems from Mighty Buildings, Boxabl, Plant Prefab, and Tuff Shed within the same single contract as your site prep and utilities. For Mighty Buildings units, we’ve completed foundation prep for their polymer composite panels, which require a flatter tolerance than conventional framing, typically ±1/8 inch over 10 feet. Our crews have the laser levels and compaction equipment to hit that spec, and we document the slab flatness with F-number testing where the manufacturer requires it.
Boxabl’s Casita units ship with integrated utility rough-ins that connect to stub-outs we prepare in the foundation. We’ve standardized the interface: our plumbing lateral terminates at a single manifold location, electrical conduit runs to a labeled junction box, and gas line extends to a tagged shutoff valve. Plant Prefab and Tuff Shed units follow similar patterns, though Tuff Shed’s post-frame construction sometimes allows us to use a simpler pier foundation in Chino’s well-draining soils. Whether you have one of these brands or any other make, we can coordinate the site prep and utilities package to match their delivery and installation schedule.
Before
AfterSigns You Need ADU Site Prep & Utilities Right Now
- Your garage slab is cracked, sloped, or less than 4 inches thick. A garage conversion ADU in Chino requires a slab that meets residential load and moisture-barrier standards. We’ve seen homeowners assume their existing garage floor is “close enough,” only to learn at plan check that the city requires a new 4-inch minimum with vapor barrier and edge insulation. The earlier you verify, the earlier we can scope the replacement.
- Your electrical panel has no open breaker slots. Tandem breakers and subpanels are stopgap solutions that inspectors increasingly reject for ADU loads. If your panel is full and dated before 1990, you’re likely looking at a full service upgrade. We can confirm with a 15-minute load calculation during your free estimate.
- Your sewer line has backed up or drains slowly. In Chino’s College Park and El Rancho neighborhoods, we’ve found tree root intrusion in original clay laterals that would never handle an additional bathroom and kitchen. A camera inspection now prevents a trench through your finished ADU pad later.
- Your gas meter is rated for 250 cubic feet per hour or less. That’s the common size for pre-2000 Chino homes, and it’s insufficient for a second dwelling with gas heat, water heating, and cooking. SoCalGas requires a meter sizing worksheet we prepare as part of the permit set.
- Your lot has visible drainage pooling or erosion channels. Chino’s winter storms can deliver 2-3 inches in a single day, and the city enforces drainage compliance strictly. If water currently collects near your proposed ADU location, the grading plan needs to address it before permit, not after construction.
Our ADU Site Prep & Utilities Process - Step by Step
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Site survey and utility mapping. We walk your Chino property with a locator to mark underground utilities, measure existing setbacks to the inch, and photograph current conditions. You receive these photos within 24 hours as the first entry in your documented photo record.
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Geotechnical and structural assessment. For foundation work, we review soil reports or commission new borings if required by Chino’s building official. For utility work, we inspect accessible portions of existing laterals and panels. Nadia Ellery reviews every finding before we quote.
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Written scope and single price. Under Haven Standard Clause 1, you receive a line-item quote with one total: foundation and grading, electrical, plumbing, gas, and landscape restoration as applicable. No allowances, no “TBD” line items, no call-for-pricing footnotes.
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Permit pull and inspection scheduling. We submit the site prep permit set concurrently with your ADU building plans, so inspections are sequenced correctly. Chino’s plan check typically runs 4-6 weeks for site prep when bundled with the full ADU package.
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Execution and documentation. Our crews work from the approved drawings, not field decisions. Every concrete pour, every trench backfill, every panel energization is photographed and added to your record. Final walkthrough confirms grade, drainage, and surface restoration match the permit set before we request final inspection.
How Much Does ADU Site Prep & Utilities Cost in Chino?
A typical foundation and grading package in Chino runs $8,000-$18,000 for a standard garage conversion slab replacement, or $12,000-$28,000 for a detached ADU with stem walls and engineered fill. Electrical panel upgrades typically fall between $3,500-$7,500 for a 200-amp service replacement, including SCE coordination and permit fees. Plumbing lateral replacement ranges $4,000-$12,000 depending on length, depth, and whether we need to trench under an existing driveway. Gas line extension is usually $2,000-$5,000 for a 30-foot run from meter to ADU, and landscaping restoration adds $3,000-$8,000 depending on hardscape complexity and irrigation rework.
What moves the price: soil conditions requiring over-excavation and engineered fill, like the expansive clays near Chino Creek; distance from your main panel to the ADU location, which affects conduit and wire sizing; and the age of your existing utilities, where we’ve found galvanized water lines and ungrounded panels that trigger full replacement rather than simple extension. What doesn’t move the price after signing: Haven Standard Clause 5 locks the scope. No door-side upsells, no “while we’re here” additions.
How to avoid overpaying: get a written line-item quote from any contractor you’re considering, then bring it to us for a Free Second Opinion. We’ll identify scope gaps, code compliance issues, or inflated allowances. Every estimate we provide includes the same documentation you’ll receive during construction: permit set, photo record, and written warranty. Call (909) 323-1107 for your free estimate.
ADU Site Prep & Utilities Near Chino - Our Service Area
We handle ADU site prep and utilities throughout Chino and the surrounding inland empire cities, including ADU Site Prep & Utilities in Chino Hills, ADU Site Prep & Utilities in Eastvale, Ontario, Montclair, Pomona, Diamond Bar, Corona, Upland, Anaheim, Rancho Cucamonga, and Fontana. Typical response for a site survey in Chino proper is within 48 hours of your call. Properties in Chino Hills or Eastvale may schedule within 72 hours depending on current permit submission volume. Every property receives the same documented photo record and written price guarantee, regardless of city.
Serving Chino, CA - Our Local Coverage Area
We’re based in the Chino area and know this community well. Use the map below to see our service coverage - if you’re nearby, we can almost certainly help.
Frequently Asked Questions - ADU Site Prep & Utilities in Chino
ADU site prep and utilities is the physical and mechanical groundwork required before or during accessory dwelling unit construction, including foundation work, grading, electrical service upgrades, plumbing sewer laterals, gas line extensions, and post-construction landscape restoration. In ADU Site Prep & Utilities in Chino, these services are typically bundled under a single contractor for garage conversions and detached ADUs, since the city requires coordinated inspections at each phase. At Ellery ADU Studio, all five sub-services are covered under one contract at one written price, with no designer-builder blame gap if something doesn’t match the permit set.
A typical site prep and utilities package in Chino takes 3-6 weeks from permit release to final inspection, assuming standard soil conditions and no utility coordination delays with Southern California Edison or SoCalGas. Foundation work with curing time accounts for 2-3 weeks; electrical, plumbing, and gas rough-ins add another 1-2 weeks; and landscape restoration finishes in 3-5 days. We sequence these trades from a single schedule, not separate contractor calendars, which is how we avoid the gaps that extend most ADU timelines. Call (909) 323-1107 to discuss your specific property’s timeline.
Most Chino homeowners pay $15,000-$45,000 for a complete site prep and utilities package, with garage conversions at the lower end and detached ADUs with full utility upgrades at the higher end. For neighboring areas, see our ADU Site Prep & Utilities in Corona. Foundation and grading represents the largest variable, electrical panel upgrade the most predictable. Every project we quote carries a written price before any work begins, per Haven Standard Clause 1, and we offer a Free Second Opinion on any written estimate you already have in hand. Call (909) 323-1107 for your specific quote.
Yes, we specify and coordinate prefab and modular systems from Mighty Buildings, Boxabl, Plant Prefab, and Tuff Shed, with foundation and utility interfaces standardized for each manufacturer’s connection requirements. For Mighty Buildings, we prepare the flatter-tolerance slab; for Boxabl, we stub out utilities to their specified manifold locations. The same single contract covers the prefab coordination and the site prep, so there’s no gap between what the factory builds and what we pour in Chino.
Stop work immediately, call 811 if the line is unmarked, and contact us at (909) 323-1107 - a live person answers 24/7. While we maintain strict utility clearance protocols and use private locators beyond the public 811 mark, accidents can happen with unmapped private lines. Our insurance and bonding covers utility strike remediation, and we document the incident with the same photo record system used throughout your project. For true emergencies involving gas leaks or energized electrical exposure, evacuate the area and call 911 first, then us.
Every site prep and utilities package is backed by our 365-Day Done Right Promise: if the finished work is not built to the permitted drawings, Ellery makes it right, in writing, before the project starts. Foundation settlement beyond normal curing, drainage that doesn’t match the approved site plan, and utility connections that fail inspection are all covered. The warranty is documented in your contract, not a verbal assurance, and Nadia Ellery personally reviews any warranty claim within 48 hours.
Gather any existing property surveys, previous permits for the main house, and recent utility bills that show your electrical and gas service sizes. If you’ve had sewer backups or drainage issues, note when they occurred and where water collects. We handle the rest: utility locating, soil assessment, and code research specific to your Chino zoning district. The estimate appointment takes 45-60 minutes, and you’ll receive your written quote within 3 business days. Call (909) 323-1107 to schedule - estimates are free, with no obligation.
Schedule Your ADU Site Prep & Utilities Service in Chino Today
Call (909) 323-1107 to schedule your free estimate. A live person answers 24/7. You’ll receive a written line-item price before any work begins, a documented photo record on every visit, and the 365-Day Done Right Promise backed in writing. Bring us any estimate you already have; our Free Second Opinion will show you what’s covered, what’s missing, and what the permit set should actually specify for your Chino property.
Written by Nadia Ellery, Owner at Ellery ADU Studio, serving Chino since 2015.