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Tremron Home Additions & ADU: The West Covina Owner’s Guide
If you’re planning a Tremron-style home addition or ADU in West Covina, you’re looking at a typical range of $45,000 to $130,000 for a room addition, and $90,000 to $220,000 for a fully permitted ADU with kitchen and bath. Mason Remodeling Co West Covina handles these projects from foundation to finish, and we’re one of the few crews in the San Gabriel Valley that will put every line item in writing before you commit. Most West Covina homeowners call us because they’ve got an aging home near Eastland Center or in the South Hills area and a growing family, or because they want rental income from a backyard unit and need someone who actually pulls permits the right way.
Here’s the honest picture: a home addition isn’t a parts swap like a faucet or a hinge. It’s framing, roofing, electrical, plumbing, insulation, drywall, flooring, and finishes, all coordinated so the new space doesn’t feel like an afterthought tacked onto the old house. What fails on these projects isn’t a single component. It’s the planning. Corners get cut on foundation ties, roofline transitions leak, or the electrical panel gets maxed out and starts tripping. If you’re reading this because a previous addition is showing stress cracks or the ADU’s subpanel keeps throwing breakers, the fix usually means opening walls and correcting what the first crew did wrong.
We’ve worked throughout West Covina for years, and we know what these older homes need. Isaac Pruett, our owner, cut his teeth on jobs just like these, and he’ll tell you the same thing he tells every client: “You should know what you’re getting before we ever pick up a tool.”
Which Tremron Models This Applies To
Tremron is best known in California for concrete pavers and hardscape products, but plenty of West Covina homeowners use Tremron pavers as part of a larger addition project, patio build-out, or ADU pathway and driveway work. So this page covers two things: the structural addition or ADU itself, and the Tremron hardscape work that typically goes with it. If you’ve got Tremron pavers on an existing patio or walkway that’s settling, cracking, or shifting as part of a failing addition, that’s a compatibility issue we see regularly.
The key gotcha with Tremron pavers on an addition project is the base. Tremron pavers are designed to sit on a compacted aggregate base with a sand setting bed. If the base wasn’t properly compacted, or if the addition’s drainage sends water under the paver field, you’ll get sinking and uneven joints within the first two rainy seasons. West Covina’s clay-heavy soil expands and contracts, which makes this worse than it is in coastal areas with sandy ground. We always check the base depth and the slope before we quote any Tremron paver work tied to an addition or ADU.
For the addition itself, there’s no “Tremron model” to match, but there are real specs that matter: the connection between old foundation and new, the roofline tie-in, and the panel load. If you’re building an ADU with a kitchen and bath, you’re almost certainly looking at a subpanel upgrade, and many West Covina homes built in the 1950s and 60s are running 100-amp or even 60-amp services that can’t handle the added load. We check that before we quote, because it’s a $3,000 to $6,000 line item some contractors leave off the bid until it’s too late.
Styles & brands we work with
Signs Your Tremron Home Additions & ADU Is Failing
- Stress cracks running diagonally from window or door corners. This usually means the foundation connection between the original house and the addition isn’t moving together. In West Covina’s clay soil, this shows up within two years if the footing wasn’t engineered right.
- Water staining or musty smell where the addition meets the original roofline. The tie-in flashing is the most common place a roof leak starts. It’s also the place that gets rushed on fast, cheap additions.
- Paver settling around the addition’s exterior. If the Tremron pavers are sinking near the foundation, water is likely pooling there and eroding the base. Every wet winter in West Covina makes this worse.
- Breakers tripping or lights flickering when the ADU’s appliances run. The panel is overloaded or the subpanel feed is undersized. This is a fire-risk symptom, not a nuisance, and it needs an electrician’s eyes on it now.
- Doors that stick in summer and close fine in winter. That’s the expansion and contraction of the addition’s framing against the original structure. It’s a sign the new section wasn’t tied properly or was framed too tight.
See the difference
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AfterReplacement Cost & What’s Included
Here are the numbers we quote in West Covina, and they’re written down on paper before any work starts:
| Project | Typical West Covina Range |
|---|---|
| Full home addition (one room) | $45,000 – $130,000 |
| ADU construction (permitted, with kitchen and bath) | $90,000 – $220,000 |
| Garage conversion to living space | $30,000 – $80,000 |
| Tremron paver patio or walkway (new or replacement) | $3,500 – $11,000 |
| Tremron paver driveway (new or replacement) | $7,000 – $18,000 |
What drives the range on an addition is the structural scope: one-story bump-outs cost less than two-story builds, and an ADU with a full kitchen and bath costs more than a studio shell. Permits, engineering, and utility connections are always included in our written price, as is the demolition and haul-away. The guarantee is 365 days from the completion date, and if anything isn’t right, we return and fix it at no charge. No dispute forms, no conditions.
DIY or Call Us?
You can safely do the inspection legwork yourself: walk the paver field after rain and look for puddles, check the roofline tie-in with a flashlight for cracked caulk or rusted flashing, and flip every breaker in your panel to see if anything trips. Those observations save us both time when we quote.
But do not try to fix a failing foundation tie or an overloaded electrical panel yourself. Foundation work on a West Covina hillside lot or a clay-soil flat lot can shift under the wrong approach, and a hot panel is a real hazard, not a weekend project. The same goes for lifting and re-setting settled Tremron pavers at the base line: if the drainage isn’t corrected first, whatever you re-set will sink again next winter. Call us at (707) 760-7579 and we’ll send someone who’s verified, background-checked, and whose name and photo you receive before they ever knock on your door.
FAQs
A properly built addition in West Covina should last as long as the original house, 50 years or more, assuming the foundation tie is engineered correctly and the drainage is kept clear. The components that fail first are the flashing at the roofline tie-in and the paver base around the exterior, both of which typically show issues within 5 to 10 years if they were installed fast and cheap. Call (707) 760-7579 if you want an honest assessment of your existing addition; the estimate is free.
Yes, and in our experience most West Covina additions can be salvaged with targeted repairs: re-flashing the roofline, sistering a few structural members, correcting the drainage, or upgrading the subpanel. The exceptions are additions built without permits, where the framing or foundation simply was never right. Those sometimes cost more to fix than to rebuild, and we’ll tell you that straight, before you spend a dollar.
A single-room addition typically takes 3 to 5 months, and a full ADU with kitchen and bath runs 4 to 8 months, depending on permit review times with the City of West Covina and the weather window for the foundation and framing. We give you a written schedule with the written price, and if a delay is coming, you hear about it from us before it surprises you.
We source Tremron pavers directly for every hardscape phase of an addition or ADU job, and we also specify KraftMaid cabinetry, Cambria quartz, and Silestone surfaces when the interior finishes come up. Everything is ordered per project from our vetted supplier network, so you’re not paying for materials that sit in a warehouse markup chain. Call (707) 760-7579 to walk through what your project needs.
Written by Isaac Pruett, Owner, Mason Remodeling Co West Covina at Mason Remodeling Co West Covina, serving West Covina and nearby areas.
