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Unilock Home Additions & ADU: The Los Angeles Owner’s Guide
Home additions and ADUs built with Unilock materials in Los Angeles typically run $53,100 to $153,400 installed, depending on square footage, foundation work, and whether you’re adding a detached unit or converting existing space. We stock the Unilock pavers, wall blocks, and coping needed for integration with new construction, and our crews handle the full build from permit drawings to final inspection, not just the hardscape layer. Most owners discover a problem when pavers shift against a new foundation line, a retaining wall begins to lean after excavation, or drainage details from the original hardscape no longer line up with the addition’s roofline.
Which Unilock Models This Applies To
Unilock’s product lines each carry their own dimensional tolerances, and that matters the moment you’re tying old hardscape into new construction. The Hollandstone and Brussels Block lines are the most common in Los Angeles additions because their 60mm and 80mm thicknesses handle the soil movement we see in the San Fernando Valley and hillside lots. The Richcliff and Beacon Hill Flagstone lines are slab-style units with tighter jointing that works well for patio and walkway integration but requires a different base prep than tumbled paver lines. The compatibility gotcha most people miss: Unilock paver thickness dictates your excavation depth and base material spec. If your original patio used 60mm units and your addition calls for a heavier-load area (driveway approach, ADU parking pad), jumping to 80mm units changes the entire base section, and you cannot simply swap one for the other without redoing the sub-base. Mason Remodeling is an independent service provider, not affiliated with Unilock, and we install both OEM Unilock product and quality aftermarket equivalents where the material spec matches. Isaac Pruett’s advice after nearly two decades of LA additions: pull one paver, measure its actual thickness with a caliper, and take a photo of the underside pattern before you order anything. The mold number is stamped there, and it settles every compatibility question in about 30 seconds.
Styles & brands we work with
Signs Your Unilock Home Additions & ADU Is Failing
- Pavers sinking or lipping at the foundation line. The excavation for your new foundation disturbed the compacted base along the old patio edge. Water follows the new concrete and erodes the sand bedding underneath the first few rows of pavers.
- Retaining wall blocks leaning or rotating after grading work. The wall’s original setback assumed one grade profile. An addition changes the slope behind the wall, adding lateral pressure the wall was never built to carry.
- Standing water pooling between the old hardscape and the new slab. The roofline of your addition now drains onto a patio that used to get sun. Without a new swale or channel drain, that water sits and undermines the bedding layer.
- Cracks radiating from any paver adjacent to a new footing. Concrete footings expand and contract at a different rate than the paver base. Without an expansion joint between the two, the pavers take the stress and split.
- Edging separation along walkways connecting the house to the ADU. Foot traffic changes when a new unit goes in. The old plastic edging under a garden path gets loaded the way a main walkway gets loaded, and it fails at the stakes first.
See the difference
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AfterReplacement Cost & What’s Included
Home additions and ADUs in Los Angeles run $53,100 to $153,400 when we’re tying Unilock hardscape into the full build. What drives the range: whether you’re converting a garage or building new on grade, how much grading and retaining wall work the lot needs, and whether the old Unilock patio gets reused or replaced as part of the project. For the hardscape portion only, you’re looking at $4,130 to $12,980 for a paver patio rebuild and $8,260 to $21,240 for a driveway that has to hold construction access first and cars after. Every Mason Remodeling project comes with a written price before any work starts, with the parts list broken out separately from labor, so you can see exactly what the Unilock material costs and what the install costs. Our work on the addition is covered by the 365-Day Done Right Promise: if the hardscape, drainage, or finished interior is not right within a year of completion, we make it right at no cost to you.
DIY or Call Us?
The honest split: you can pull a few pavers to check the base condition, photograph the mold stamps, and map where water pools after a rain. That is genuinely useful information and it helps us price the job faster. What you should not do is regrade a slope behind a retaining wall, excavate a foundation-adjacent base, or reset pavers within three feet of a new slab. The pressure behind a retaining wall on a hillside lot in Los Angeles is substantial, and a wall that lets go during construction is dangerous. If the wall is leaning more than a few degrees or you see cracks wider than an eighth of an inch in the blocks, call (803) 680-2547 and let us look before anyone digs.
FAQs
Unilock pavers installed on a properly compacted base in Los Angeles typically last 25 to 40 years before the base needs full reconstruction, though the surface units themselves often stay intact and reusable. Our climate’s limited freeze-thaw cycles help, but UV exposure and drought-driven soil movement are the real enemies here.
If the failure is limited to bedding sand erosion, edge restraint, or a localized drainage issue, the affected section can usually be lifted, re-based, and reinstalled without replacing the pavers. If the base itself has failed from water or improper initial compaction, full excavation and rebuild is the only fix that lasts. Call (803) 680-2547 for an honest assessment, and our estimate is free either way.
A paver patio rebuild or addition-integrated hardscape installation typically takes 5 to 10 working days from demolition to final compaction, depending on square footage and whether retaining wall work is involved. Full home additions and ADUs run longer, and we give you a written timeline with the written price before work starts.
We keep common Unilock Hollandstone and Brussels Block units, edge restraints, and drainage components stocked for Los Angeles jobs, and special-order slab lines like Richcliff arrive within a week. If you need an exact match on an older paver, we pull from the mold stamp and match it before the crew arrives.
Call (803) 680-2547 to schedule your free estimate. We’ll walk the site, check the base, identify the Unilock product, and hand you a written price for the exact scope of work, no surprises, no change orders. Know who’s coming, know what it costs, know it’s backed up. Everything else is just noise.
Written by Isaac Pruett, Owner, Mason Remodeling at Mason Remodeling, serving Los Angeles and nearby areas.
