Free written scope consultation - allowances, timeline, and change-order rules on paper before a single trade is scheduled
Blanco Home Additions & ADU: The West Covina Owner’s Guide
Adding onto a Blanco home or building an ADU on the property typically costs between $45,000 and $130,000 in West Covina, depending on square footage, foundation work, and what’s behind the walls when we open them up. Most owners call us after living with a space that no longer works: a kitchen that’s too tight for two people, a garage that never fit a car anyway, or aging parents who need to be closer than a 40-minute drive. The discovery usually happens slowly, then all at once. You realize the square footage that worked five years ago doesn’t anymore, and you’re tired of talking yourself out of doing something about it.
We’re Mason Remodeling Co West Covina, and while we’re not affiliated with Blanco, we’ve worked on Blanco-built homes throughout West Covina for years, including projects near Eastland Center where the original layouts were tight and the electrical panels from the 1970s needed real attention before any walls could move. You should know what you’re getting before we ever pick up a tool. That’s why we put a written price in front of you before anything starts.
Which Blanco Homes & ADU Projects This Applies To
Blanco homes in West Covina fall into a few recognizable patterns. Single-story ranch layouts from the 1950s and 1960s dominate the older neighborhoods, where additions typically mean pushing out the back wall or converting an attached garage into living space. Two-story builds from the 1970s and 1980s have a different set of constraints: load-bearing walls that can’t simply disappear, rooflines that complicate a second-floor addition, and foundation footings that were poured for one story, not two.
The first thing we do on any Blanco home addition or ADU is identify what type of foundation you have. Raised foundations are common in West Covina and are generally easier to tie a new addition into. Slab-on-grade is a different process, requiring saw-cutting, doweling rebar, and sometimes a new sub-panel for the added electrical load. An ADU, whether it’s a detached unit in the backyard or a garage conversion, carries its own specific code requirements in West Covina, including setback rules, fire-rated separation walls, and minimum ceiling heights. We pull those permits and we know what the inspectors expect before we submit anything.
When it comes to materials and finishes, we install specification-grade products from KraftMaid, Cambria, and Silestone, plus Blanco fixtures where the existing plumbing layout makes sense to reuse. The decision on OEM versus aftermarket doesn’t apply the same way to a full addition as it does to a single part: we’re building structure, not replacing a failing component. What matters is matching the new work to the existing home so it doesn’t look bolted on.
Styles & brands we work with
Signs Your Blanco Home Additions & ADU Is Failing
- Doors that stick or won’t latch in the summer. West Covina heat and the region’s shrink-swell clay soil can shift a foundation enough to throw door frames out of square. It’s a slow problem until it isn’t, and it often shows up first on the back of the house where the afternoon sun hits hardest.
- Cracks in the drywall at the original-to-addition seam. If a previous owner added square footage, and the seam between old and new starts cracking, moisture or settling is at work. The fix usually involves more than taping and mudding; we want to know what’s moving underneath first.
- The garage conversion runs hot and cold with the seasons. Unpermitted conversions are everywhere in West Covina. If your converted space was never properly insulated, never got its own HVAC run, and the walls feel like an oven by 2 PM, you’re paying for comfort you never actually got.
- Electrical breakers trip when you run the microwave and toaster together. Older Blanco homes weren’t wired for modern kitchens. When addition plans include any new appliances, we check the panel capacity early. Replacing a 100-amp panel is far cheaper to do as part of the project than two years later.
- You can feel the floor bounce when someone walks across it. That’s typically undersized joists, and it matters for any second-story addition or ADU loft. We never build new living space on a structure that deflects more than code allows.
See the difference
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AfterReplacement Cost & What’s Included
A Blanco home addition in West Covina runs $45,000 to $130,000. ADU construction sits above that, at $90,000 to $220,000 for a detached unit, while a garage conversion lands between $30,000 and $80,000. What drives the range? Foundation type, kitchen or bath count in the new space, electrical service upgrades, and how much of the existing structure has to be corrected before new walls go up. Older Blanco homes often have surprises behind the drywall: cast iron drains, aluminum wiring, or framing that was fine in 1962 but doesn’t meet current shear-wall requirements.
Our written price includes the full scope: demolition, foundation, framing, rough electrical and plumbing, drywall, finishes, and the final inspection. It’s not an estimate that grows later. We include permit costs and we stand behind the work for 365 days from the completion date under our 365-Day Done Right Promise. If something isn’t right within a year, we return and make it right at no cost to you.
DIY or Call Us?
We’ll be straight with you: a home addition or ADU isn’t a weekend project, and trying to act as your own general contractor on a project this size causes more problems than it solves. What you can do, safely, is assess your existing space. Walk your property line and check setbacks. Look for cracks in the stem wall. Open the electrical panel and read the main breaker rating. If it says 100 amps and you want a full kitchen and laundry in your ADU, budget for an upgrade.
What you shouldn’t do is pull your own permits, pour concrete, or gut load-bearing walls without an engineer’s stamp. West Covina’s building department enforces seismic codes that exist because we live in earthquake country. If either the framing or the foundation is wrong, the failure shows up in an inspection or, worse, after the first big quake. Every crew member we send to your home is background-checked and identity-verified under our company’s Threshold Standard. You’ll get the technician’s name and photo before the visit, and they’ll show a photo ID badge at your door. Call (707) 760-7579 for a free estimate and we’ll walk you through what your Blanco home can support.
FAQs
A typical garage conversion takes 8 to 12 weeks once permits are approved, while a full addition or detached ADU runs 4 to 7 months depending on scope. Permit review times in West Covina vary by season and project size. Call (707) 760-7579 and we’ll give you a realistic timeline based on your specific lot and plans before you commit to anything.
Yes, in many cases we can. Cracked seams, poor insulation, failing doors, and undersized electrical can often be corrected without tearing everything down. Repair costs range from a few thousand dollars for selective fixes to a full rework that approaches new-construction pricing. The free estimate will show you the actual line items either way.
We order structural materials per project, but we keep professional-grade finish products available through our supplier partnerships with KraftMaid, Cambria, Silestone, and Blanco. This isn’t big-box off-the-shelf material; it’s cabinet and countertop stock that holds up to the daily wear a West Covina household puts on it.
No. Your written price is delivered before we start work, and it’s based on our own inspection of your home’s current condition. We don’t write change orders unless you ask us to expand the scope. If we find something unexpected behind a wall, we talk through the options and the cost before doing anything, never after.
Written by Isaac Pruett, Owner, Mason Remodeling Co West Covina at Mason Remodeling Co West Covina, serving West Covina and nearby areas.
