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Unilock Home Additions & ADU: The Los Angeles Owner’s Guide
A Unilock home addition or ADU project in Los Angeles typically runs $53,100 – $153,400, depending on square footage, foundation work, utility runs, and whether you’re tying into the existing roofline. The work usually takes 4 to 8 months from permit to final inspection. What most LA homeowners discover first isn’t a failed “part” in the traditional sense: it’s a failed connection, whether that’s a paver base shifting under a Unilock walkway tying the addition to the main house, or a Unilock retaining wall pulling away because the original contractor skipped proper drainage behind it.
We’re Penhallow Remodeling Los Angeles, an independent remodeling company, not affiliated with Unilock. We work with Unilock pavers, retaining walls, and outdoor living systems in home addition and ADU buildouts because they hold up in our dry summers and occasional heavy winter rain, but only when the substrate and drainage underneath are done right. Our owner, Trevor Nash, will tell you plainly what a job costs before he ever picks up a hammer.
Which Unilock Models This Applies To
In Los Angeles, the Unilock products we most often install (and repair around) are the Estate Wall, Brussels Block, Lineo Dimensional Stone, and U-Cara Multi-Face Wall System lines. Each has a different locking profile and recommended base depth, and getting the wrong unit size or series creates visible gaps or shifting within the first wet season.
The key identification step: Unilock stamps a product code and batch date on the underside of most manufactured units. If you have leftover pavers or wall units from the original build, flip one over and write down the code before you call anyone. The code tells you the series, the plant, and the production run, which matters because color lots can vary enough between batches that a replacement paver looks like a different stone. If you don’t have a spare unit, measure a full unit (length × width × depth in inches) and take a clean photo against a tape measure.
OEM Unilock units are the straightforward call. Quality aftermarket equivalents exist for some paver profiles, but with Unilock specifically, the dimensional tolerances are tight enough that mixing brands on a visible walkway or wall usually looks off and locks unevenly. We source direct from Unilock through local Los Angeles distributors, and because we’re buying for active buildouts, we can often match an existing lot or pull from current stock faster than a homeowner ordering single units.
Styles & brands we work with
Signs Your Unilock Home Addition or ADU Connection Is Failing
- Pavers sinking or cupping at the addition’s door threshold. Nearly always a base failure: too shallow, wrong aggregate, or missing compaction. Los Angeles clay soil expands and contracts more than most people expect, and a 4-inch base instead of a 6- to 8-inch base shows up as a dip within two rainy seasons. The fix is not adding sand on top; it’s pulling the section, rebuilding the base, and releveling.
- Retaining wall leaning or bulging. Behind almost every failing Unilock wall in LA is water. If the original installer skipped a perforated drain pipe, gravel backfill, or filter fabric, hydrostatic pressure pushes the wall face outward a few inches at a time. You’ll often see the top units starting to separate from the ones below them.
- Gaps opening between pavers at the joint line between old and new work. Additions and ADUs settle at a different rate than the main house. Without a proper expansion joint or transition detail, that differential movement shows up as a widening gap. The paver didn’t fail; the detailing did.
- Efflorescence or mineral streaking on wall faces. White powdery deposits mean water is moving through the wall system where it shouldn’t be. It’s cosmetic at first, but repeated cycles of water behind a wall will eventually push units, crack caps, or freeze-spall in the rare LA cold snap above the Basin.
- Loose or rocking coping caps on a Unilock wall. Caps are usually adhered with a masonry adhesive. If the installer used the wrong adhesive or skipped cleaning the surface, you’ll feel movement underfoot. That’s a safety issue on a seating-height wall and an entry point for water.
See the difference
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After
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AfterReplacement Cost & What’s Included
Repair work on Unilock systems tied to an LA home addition or ADU runs from a few thousand dollars for a small wall repair up to $20,000 – $40,000+ for rebuilding a failing wall face or redoing a large paver area with proper base. Full addition and ADU projects that integrate Unilock products from the start run $53,100 – $153,400 as a total build, not a parts-only figure.
What drives the range:
- Access. If the failed section is behind a locked gate, down stairs, or in a narrow side yard in neighborhoods like Eagle Rock or Highland Park, labor hours climb because every unit goes in by hand.
- Base condition. If we pull pavers and find no gravel, no fabric, or sand only, that’s a base rebuild, not a paver swap. The base is often two-thirds of the correct repair.
- Wall height and engineering. In Los Angeles, any retaining wall over 3 feet typically requires a permit and an engineered design. Wall height changes the fix from a weekend repair to a permitted structural project.
- Matching work. Reusing in-place units when they’re structurally sound keeps cost down. Replacing an entire wall face with new Unilock units means buying new units, new caps, adhesive, and often new drainage materials.
Every repair we do includes a written price before we start and the 365-Day Done Right Promise: if our work fails inside the guarantee period, we come back and fix it at no charge. That’s in writing on every project, not a verbal assurance.
DIY or Call Us?
Here’s the honest split. You can safely check a few things yourself: photograph the failed area from multiple angles, measure the units, write down any product codes from the underside of spare pavers, and verify whether water pools near the wall or paver edge during rain. That information saves us a full diagnostic visit and helps us price the repair accurately before we arrive.
What you shouldn’t do is dig into a retaining wall or pull paver units yourself. Walls over 3 feet carry real load, and removing the wrong units without shoring the ones above can turn a $4,000 repair into a wall rebuild. Additions and ADUs also involve utility lines in the ground around the footprint, and digging without a utility locate (we handle that, it’s included in our process) is a genuinely dangerous way to learn where the gas line runs.
Trevor grew up in the Crenshaw district and still lives a few miles from there. He studied construction technology at Los Angeles Trade-Technical College, and he’s spent two decades watching what happens to hardscape when the base is skipped and the water isn’t managed. His rule for any job: give you a number first, then pick up the tools. Call (213) 277-6578 and we’ll walk the site, write the price, and tell you exactly what’s below the surface before any unit comes out.
FAQs
A properly installed Unilock wall or paver system in Los Angeles lasts 25 to 40 years or more, because the concrete units themselves barely wear here. What shortens that lifespan is almost always underneath: insufficient base, missing drainage, or tree roots from mature ficus and magnolia trees common in LA yards pushing through from below. Call (213) 277-6578 and we’ll tell you honestly whether your failure is the product or the installation.
Yes, in many cases, especially with wall lean or paver sinking. If the units themselves aren’t cracked or spalled, we can often reuse them after rebuilding the base and adding proper drainage. That saves thousands in material costs and keeps your color lot consistent across the whole surface. We’ll give you a reuse-versus-replace number in the written estimate, not after the demo starts.
A focused paver relevel or small wall repair usually takes 1 to 3 days. A larger rebuild with drainage and base work runs 1 to 2 weeks. Full additions and ADU projects with Unilock elements run 4 to 8 months from permit to final, depending on DWP and LADBS timelines in Los Angeles. We’ll give you a real arrival window before work starts and keep it.
We keep common Unilock repair materials on hand: joint sand, base aggregate, filter fabric, drain pipe, and masonry adhesive. Specific Unilock units are sourced from local Los Angeles distributors once we confirm the product code and color lot from your existing installation. That ordering step usually adds 2 to 5 business days to a repair schedule, but it’s the only way to guarantee a visual match. We also work with KraftMaid, Cambria, and Silestone materials on the interior side of addition and ADU builds, so the same crew that fixes your walkway can quote the kitchen that looks onto it.
Written by Trevor Nash, Owner, Penhallow Remodeling Los Angeles at Penhallow Remodeling Los Angeles, serving Los Angeles and nearby areas.
For a free estimate on your Unilock repair or home addition in Los Angeles, call (213) 277-6578. We’ll give you a written number before any work starts, and stand behind it for 365 days.
