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Unilock Home Additions & ADU: The Santa Clarita Owner’s Guide
If you’re planning a Unilock home addition or ADU in Santa Clarita, you’re looking at an installed cost between $45,000 and $130,000 for a home addition, and $90,000 to $220,000 for a full ADU construction. We’re Sawyer Remodel Santa Clarita, and we handle the complete structural and finish work for these projects, including paver hardscape integration that many Unilock owners want matched to their existing patios and walkways. Most homeowners reach out after they’ve realized their existing Unilock pavers need to be tied into a new foundation or addition slab, and they want a contractor who understands both the masonry side and the framing side of that junction.
We’re an independent general contractor serving Santa Clarita and the surrounding areas. We’re not affiliated with Unilock. But we work with their pavers and retaining wall systems every week, and we know how to make a new addition sit right against existing Unilock work without creating drainage problems, uneven transitions, or frost-heave issues that show up two winters later.
Key Takeaways:
- Home additions in Santa Clarita run $45,000 to $130,000 installed; ADU construction runs $90,000 to $220,000
- We integrate existing Unilock pavers, walls, and steps into new addition foundations and slabs
- Written price before any work starts, with the 365-Day Done Right Promise backing every project
- Call (661) 592-1977 for a free estimate on your addition or ADU
Which Unilock Models This Applies To
Unilock doesn’t make home additions or ADUs, so there’s no model number to match. What matters is which Unilock products you already have on your property, because the junction between old paver work and new construction is where most Santa Clarita jobs go sideways. We regularly work with Unilock’s Beacon Hill, Courtstone, Brussels Block, and Richcliff lines, along with their Estate Wall and Pisa retaining wall systems. If you’ve got a Unilock paver patio, driveway, or walkway that will be partially removed or tied into a new addition, the compatibility question is about base compaction, edge restraint, and elevation, not part numbers.
Here’s the compatibility gotcha most homeowners don’t catch: a new addition slab next to existing Unilock pavers will settle at a different rate than the paver base. In Santa Clarita’s clay-heavy soil, especially around Valencia and Saugus, that differential settlement can create a visible lip within 18 months if the new foundation isn’t keyed correctly and the paver edge isn’t restrained. We run a compacted aggregate base under any new paver tie-in, set the edge restraint before the slab pour, and grade the transition so water moves away from the foundation. That’s not standard practice with every contractor, but it’s the only way we do it.
OEM vs. aftermarket for Unilock-specific work: when we’re extending a patio or walkway with new Unilock pavers, we specify genuine Unilock product so the color, texture, and joint width match. Aftermarket pavers look close in a showroom and wrong in your backyard, especially after a season of sun. For the structural parts of the addition itself, lumber, concrete, and framing are spec’d to Santa Clarita building codes, not a brand label. You get the manufacturer-backed product where it’s visible, and code-compliant structure where it isn’t.
Styles & brands we work with
Signs Your Unilock Home Additions & ADU Is Failing
- Heaving or sinking pavers at the addition junction. This is almost always a base-compaction failure. In Santa Clarita’s clay soil, paver bases that weren’t compacted in lifts will shift with seasonal moisture changes. The pavers near the new slab drop, and you get a tripping hazard right at your back door.
- Water pooling against the new foundation after rain. If the grade wasn’t set correctly when the addition went in, runoff sits against the slab instead of flowing to a drain or swale. You’ll see efflorescence on the foundation, damp carpet at the wall base, or efflorescence on the Unilock pavers themselves. That’s a drainage problem, not a paver problem, and it won’t fix itself.
- Separation between the addition wall and the existing structure. Hairline cracks that widen, drywall seams that open, or a visible gap at the roofline are signs of settlement or inadequate tie-in. Santa Clarita sees enough temperature swing and soil movement that a poorly keyed addition will pull away from the original house within a few years.
- Cracking in the new slab or stem wall. Concrete cracks for a lot of reasons, but a pattern of diagonal cracks running from the corners of an addition slab points to inadequate compaction of the subgrade or missing rebar. In Valencia and Stevenson Ranch, where fill soil is common, this shows up more often than anyone admits.
- Doors and windows in the addition that stick or won’t latch. That’s the frame racking or settling. When a door that swung fine in November won’t latch in March, the addition is moving. It’s not a hardware issue; it’s a structural one.
See the difference
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After
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After
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AfterReplacement Cost & What’s Included
For a home addition in Santa Clarita, the installed range is $45,000 to $130,000. A full ADU runs $90,000 to $220,000. That’s what Luca Romano and our crew at Sawyer Remodel Santa Clarita see across Valencia, Saugus, Canyon Country, and Newhall. The spread is driven by square footage, foundation type, roof tie-in complexity, and how much Unilock hardscape integration is involved. A simple bump-out addition with a crawlspace foundation lands at the lower end. A second-story addition or a detached ADU with new utility runs, a kitchenette, and a full paver patio connection lands at the upper end.
We put every price in writing before any work starts. You’ll see line items for excavation, foundation, framing, roofing, electrical, plumbing, drywall, paint, and the Unilock paver tie-in if there is one. No change-order surprises, no “we didn’t expect that” invoice at the end. The number you approve is the number you pay. And every project carries the 365-Day Done Right Promise: if it’s not done right, we make it right, backed in writing.
Garage conversions, which fall between a full addition and a small remodel, run $30,000 to $80,000 in Santa Clarita. If you’re weighing a garage conversion against a new ADU, that’s the number to anchor on.
DIY or Call Us?
If your question is about the Unilock pavers around an existing addition, there are a few checks you can safely do. Look for gaps at the edge restraint, check whether the paver surface dips toward the foundation, and feel for loose pavers underfoot. Identifying a problem is fine. Fixing it is a different story.
Lifting and re-setting pavers, re-compacting a base, and re-grading drainage against a foundation is not a weekend project. Adding a room or building an ADU is absolutely, unambiguously not a DIY project. We’re talking foundation excavation, engineered beams, roof tie-ins, electrical panels, and gas lines. A mistake in any of those is a safety risk, not a cosmetic flaw. And if you try to pull a permit as a homeowner and then call us halfway through, you’ll pay more to fix the failed inspection than the original job would have cost.
We show up with background-checked, uniformed crew members, a written price in hand, and a timeline we actually keep. Call (661) 592-1977 and we’ll schedule a free estimate. The work tells the story. We just show up and do it right.
FAQs
A home addition typically takes 4 to 8 months from permit pull to final inspection. A detached ADU runs 6 to 12 months depending on utility work and site prep. Santa Clarita’s planning and permitting timeline, especially for ADUs in the City of Santa Clarita jurisdiction, can add 4 to 8 weeks before demo even starts. We handle the permits and keep you updated with photo updates before and after each phase. Call (661) 592-1977 if you want a project timeline specific to your property.
Yes, in most cases. We lift and palletize the pavers in the construction zone, protect the remaining hardscape, and re-install them once the addition is closed in. Some breakage is inevitable, so we order a matching overage of the same Unilock line at the start. If your paver line is discontinued, we’ll match as closely as possible with the same color family and surface finish. Call (661) 592-1977 for an exact assessment.
No. The written price you approve before permits is the price you pay. The only exceptions are if you change the scope, or if the city inspection exposes a code issue hidden inside an existing wall. We don’t pad estimates, and we don’t hit you with a change order because we forgot to include something. That’s the Relay Visibility Guarantee, and it’s not optional on our jobs.
Yes. Every addition and ADU we build gets permitted, inspected, and closed out with the City of Santa Clarita. We pull the permits, schedule the inspections, and you get a finished job that has a legal paper trail. Unpermitted additions are a liability when you sell the house, and the city does catch them. Call (661) 592-1977 to schedule a free estimate and we’ll walk you through the permit path before you spend a dime.
Written by Luca Romano, Owner, Sawyer Remodel Santa Clarita at Sawyer Remodel Santa Clarita, serving Santa Clarita and nearby areas.
