Trusted ADU Site Prep & Utilities for West Hollywood Homeowners
Our ADU Site Prep & Utilities - West Hollywood guide explains that this work typically costs $35,000-$95,000 depending on scope, with foundation and grading work starting around $18,000 and full utility package upgrades reaching the higher end for hillside properties or older electrical panels. Ellery ADU Studio has designed, permitted, and built over 900 ADUs since 2015, and every site prep and utilities package comes with a written price before any work begins, per Haven Standard Clause 1. Call (213) 329-7167 to schedule your free estimate - a live person answers 24/7.
West Hollywood’s compact lots, aging infrastructure, and strict hillside grading requirements make site prep one of the most underestimated phases of ADU construction. We’ve seen too many projects stall when a homeowner discovers their 100-amp panel cannot support a second dwelling, or when a post-war concrete slab fails compaction tests for a garage conversion. Our design-build studio handles the drawings, permits, and construction under one contract at one written price, so no one can blame the designer when the builder hits rock at 18 inches, or blame the builder when the setback variance wasn’t flagged in the permit set.
What Our ADU Site Prep & Utilities Service Includes
Foundation & Grading
Foundation and grading is the physical preparation of your lot to receive an ADU, including soil compaction, excavation, retaining walls for hillside lots, and the concrete slab or stem wall that the unit sits on. In West Hollywood, you’ll need this for any new detached ADU, and often for garage conversions where the existing slab is too thin, cracked, or built without a vapor barrier. We specify and coordinate foundation systems for prefab brands including Abodu and Cover units, and we document every compaction test and rebar layout with photos you receive before the pour.

Electrical Panel Upgrade
An electrical panel upgrade replaces your existing service panel with one that can handle the additional load of a second dwelling, typically from 100 amps to 200 amps for most West Hollywood ADUs. You’ll need this when your main panel is full, uses outdated Zinsco or Federal Pacific breakers, or when LADWP requires a new service lateral for the ADU meter. We pull the permit, coordinate LADWP scheduling, and include the panel, breakers, grounding, and final inspection in your written price - no electrician subcontractor billing you separately.

Plumbing Lateral
A plumbing lateral is the underground pipe that connects your ADU’s water supply and sewer line to the city main, often requiring trenching through established landscaping or narrow West Hollywood side yards. You need this for any ADU with its own kitchen or bathroom, which is nearly all of them, and many 1920s-1950s homes in the Norma Triangle or Spaulding Square still have original clay or cast-iron laterals that cannot handle the additional flow. We camera-inspect the existing line, specify ABS or PVC replacement where needed, and restore your hardscape after backfill.

Gas Line Extension
Gas line extension runs a new buried line from your existing meter or main to the ADU location, sized for the water heater, furnace, range, or fireplace you specify. You’ll need this for any gas-heated ADU, and Southern California Gas Company often requires a pressure test and new shutoff valve for extensions over 50 feet - common in West Hollywood’s deeper lots north of Sunset. We size the line per BTU load, pull the SoCalGas permit, and pressure-test before cover, with documentation sent to you same-day.

Landscaping & Hardscape
Landscaping and hardscape restoration returns your yard to usable condition after trenching, grading, and construction, including irrigation repair, concrete or paver walkways, and drought-tolerant planting required by West Hollywood’s water conservation ordinances. You need this because LADWP and the city inspector will not sign off on final occupancy if your yard is left as bare mud or unstable fill. We specify materials that match your existing hardscape, coordinate with James Hardie siding colors where applicable, and include the restoration in your original written scope - not as a surprise add-on after the backhoe leaves.

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’ve specified and coordinated site prep for hundreds of Abodu units across Los Angeles County, including their One and Two models that require a 4-inch reinforced slab with specific anchor bolt patterns. Our permit sets include the foundation details Abodu requires for their structural warranty, and we coordinate their crane-set delivery with our grading schedule so your slab cures precisely on time.
We’ve also prepped sites for Tuff Shed’s Studio Shed Pro line and James Hardie siding packages on custom stick-built ADUs, including the moisture-management details that Hardie’s 30-year warranty requires for coastal-adjacent West Hollywood. Whether your project uses Abodu, Cover, Tuff Shed, James Hardie, or any other system, we specify the exact site prep and utility connections that brand requires, in the same single contract that covers your design, permits, and build.
Before
AfterSigns You Need ADU Site Prep & Utilities Right Now
- Your main electrical panel is labeled 100 amps or has no empty breaker slots. LADWP will not approve a second meter without adequate service capacity, and upgrading after your ADU is framed means opening walls you just closed. We verify your panel capacity during the free estimate and include the upgrade in your written price if needed.
- Your garage floor has cracks wider than a quarter-inch, or slopes toward the house. This indicates settlement, inadequate compaction, or missing reinforcement - all of which will fail inspection for a garage conversion ADU. We core-test the slab thickness and specify replacement or overlay in the permit set before you sign.
- Your water pressure drops when two fixtures run simultaneously. This suggests an undersized supply line or galvanized piping that cannot support an ADU’s additional demand. We pressure-test your system during evaluation and specify the lateral replacement size in your quote.
- Your property sits on a hillside or has visible slope toward the foundation. West Hollywood’s northern lots above Sunset Boulevard often require retaining walls and engineered fill per the city’s hillside grading ordinance. We survey your grade, specify the geotechnical report if required, and design the retaining system into your permit set.
- You smell gas near your meter or have an original 1950s gas line. SoCalGas requires leak-free, properly sized lines for any extension, and old steel pipes corrode from the inside out. We pressure-test your existing line and specify replacement or extension in your written scope, with no change orders after signing.
Our ADU Site Prep & Utilities Process - Step by Step

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Site evaluation and utility mapping. We visit your West Hollywood property with a licensed electrician and plumber, locate your electrical panel, water meter, sewer cleanout, and gas meter, and photograph existing conditions. You receive these photos within 24 hours, with annotations explaining what we found and what it means for your project.
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Geotechnical and structural assessment. For new detached ADUs or hillside lots, we order a soils report and survey your property lines, setbacks, and slope stability. For garage conversions, we core-test the slab and check for vapor barriers, termite damage, and adequate thickness. Every finding is documented with photos and written into your scope.
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Permit set preparation and submission. Our in-house designers produce the site plan, utility plan, and structural drawings that West Hollywood Building & Safety requires, including LADWP and SoCalGas coordination letters. The permit set is the core product of our studio - not outsourced, not an afterthought.
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Utility coordination and scheduling. We submit to LADWP for electrical service upgrades, to SoCalGas for line extensions, and to the city for sewer connection permits. Our permit expediter tracks each submission, and we schedule our work around utility availability, not the other way around.
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Construction, inspection, and documentation. Our background-checked, uniformed crews execute the work per the permitted drawings, with a photo record of every trench, every conduit run, and every compaction test. Final inspection is scheduled only when we confirm every detail matches the permit set - backed by our 365-Day Done Right Promise.
How Much Does ADU Site Prep & Utilities Cost in West Hollywood?
See our ADU Site Prep & Utilities cost guide for typical pricing: an electrical panel upgrade in West Hollywood runs $4,500-$8,500 depending on whether LADWP requires a new service lateral or overhead-to-underground conversion. Foundation and grading for a flat lot starts around $18,000 and climbs to $35,000+ for hillside properties requiring retaining walls and engineered fill. Plumbing lateral replacement ranges $6,000-$14,000 depending on trench length and whether we hit the original clay pipe. Gas line extension typically runs $3,500-$7,500. Landscaping and hardscape restoration after utility work adds $5,000-$12,000 depending on materials and irrigation complexity.
What moves your price within these ranges: soil conditions (rock or expansive clay adds excavation cost), utility distance from the ADU location, existing infrastructure age and material, and whether your property falls under West Hollywood’s hillside grading ordinance requiring a geotechnical report. How to avoid overpaying: get a written line-item quote before any work starts, verify the contractor’s license number appears on the estimate, and confirm permit costs are included, not billed separately. Under Haven Standard Clause 1, every Ellery project receives a written price before work begins - no verbal estimates, no “we’ll figure it out as we go.”
Your free estimate includes a site visit, utility capacity check, photo documentation of existing conditions, and a written scope with line-item pricing. If you already have a written estimate from another contractor, we’ll provide a Free Second Opinion comparing their scope to ours, clause by clause.
ADU Site Prep & Utilities Near West Hollywood - Our Service Area

We serve West Hollywood and surrounding communities including Studio City, Los Angeles, North Hollywood, Culver City, Sherman Oaks, Burbank, Santa Monica, Van Nuys, Westchester, Inglewood, and Glendale. Most West Hollywood properties receive initial site evaluation within 48 hours of calling, and we maintain active permit relationships with West Hollywood Building & Safety, LADWP, and SoCalGas to keep your project moving. ADU site prep and utilities in Los Angeles follows similar requirements, though each jurisdiction has specific inspection scheduling quirks we’ve learned since 2015.
Serving West Hollywood, CA - Our Local Coverage Area
We’re based in the West Hollywood 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 West Hollywood

ADU site prep and utilities is the ground-up preparation and infrastructure connection required before your accessory dwelling unit can be built and occupied, including foundation work, grading, electrical service, water and sewer lines, and gas connections. You need it because West Hollywood Building & Safety will not issue a certificate of occupancy without permitted, inspected utility connections and a structurally adequate foundation. Every Ellery project includes these elements in a single written scope, so nothing is missed between design and build.
Most site prep and utility packages take 4-8 weeks from permit issuance to final inspection, with electrical panel upgrades and gas line extensions typically moving fastest and hillside grading with retaining walls taking longest. LADWP scheduling for service upgrades can add 2-4 weeks depending on their backlog, which we factor into your project timeline during the estimate. Call (213) 329-7167 for a schedule specific to your property - estimates are free.
Complete site prep and utilities for a typical West Hollywood ADU runs $35,000-$95,000 all-in, with smaller utility-only packages starting around $15,000 and full hillside grading with retaining walls reaching the upper end. Your specific price depends on existing infrastructure condition, lot slope, utility distances, and whether you’re converting a garage or building new. We provide a written line-item quote before any work begins, per Haven Standard Clause 1 - call (213) 329-7167 for yours.
Yes, we specify and coordinate site prep for Abodu, Cover, and other prefab and modular systems, including their exact foundation specifications, utility connection points, and crane-set requirements. Our permit sets include the manufacturer-specific details their warranties require, and we coordinate delivery timing with our construction schedule. Whether you have Abodu, Cover, Tuff Shed, or a custom design, we handle the site prep under the same single contract.
We do not perform emergency utility repair - our work is planned construction, not emergency service, and we do not promise same-day dispatch for site prep. If you have an active gas leak or electrical hazard, contact SoCalGas or LADWP emergency lines immediately. For planned ADU projects, we schedule site evaluation within 48 hours and begin work after permit approval and your written authorization.
Our 365-Day Done Right Promise covers all site prep and utilities work: if the finished foundation, electrical, plumbing, or gas installation is not built to the permitted drawings, we make it right in writing. This is backed by Haven Standard Clause 5 (No Surprises), which locks your scope at signing with no door-side upsells or scope creep. You also receive a documented photo record of every construction visit, so you have evidence of what was installed and when.
Clear access to your electrical panel, water meter, gas meter, and sewer cleanout, and locate any property surveys or previous permit documents you have. If your home was built before 1960, note any previous additions or unpermitted work, as these affect setback calculations and utility capacity. We’ll handle the rest during our visit, including photos, measurements, and utility capacity checks - call (213) 329-7167 to schedule, and a live person will answer.
Schedule Your ADU Site Prep & Utilities Service in West Hollywood Today
Call (213) 329-7167 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 of every visit, and the 365-Day Done Right Promise backed in writing. If you already have a written estimate from another contractor, ask for our Free Second Opinion - we’ll compare scopes clause by clause, no obligation.
Written by Nadia Ellery, Owner at Ellery ADU Studio, serving West Hollywood since 2015.