How Ellery ADU Studio Corona Was Born in Corona
We remember the exact afternoon in 2015 when the phone rang in our kitchen. A homeowner in Corona’s Sierra Del Oro neighborhood had hired a designer for an ADU, then a separate builder, and now sat between two contractors who each blamed the other for a foundation pour that missed the setback by fourteen inches. The city had red-tagged the job. She was out $34,000 with nothing standing but a slab that needed jackhammering.
We drove over that evening. The concrete was still green enough to scar with a boot heel. What struck us wasn’t the technical failure, it was the paperwork, or the lack of it. No single contract. No single throat to choke. The designer pointed to the builder’s field adjustment; the builder pointed to the designer’s dimension. We spent three hours on her porch with a tape measure and the Corona municipal code, mapping how a single-source contract would have caught the error at the permit stage.
That night we called the parent company and asked to bring the Ellery model here. One price. One contract. One person who answers for the drawings and the build. Corona’s ADU market was about to explode, California’s laws had just shifted, and we weren’t going to watch another homeowner become a coordinator between two vendors who each made money from the confusion.
Nadia Ellery’s Personal Connection to the ADU Trade
I got into this work sideways, through frustration with how houses actually get built.
Before Ellery, I spent years watching the construction process from the edges, first as a permit expeditor in Riverside County, then as a project coordinator for a firm that built spec homes in Eastvale and Mira Loma. The work was fine. The waste wasn’t. I’d see a homeowner spend eight months on drawings, another six in permit review, then hand those same drawings to a builder who treated them as suggestions. The smell of that process, honestly, was coffee gone cold in conference rooms where no one had read the structural notes.
What changed me was a job in El Cerrito, spring of 2014. A retired couple had saved for fifteen years to build a backyard unit for their daughter, who was coming home from overseas with a spinal injury. The designer had drawn a beautiful plan. The builder had poured the foundation before the fire department signed off on the access width. By the time I got involved as a coordinator, the daughter was sleeping in the living room and the couple was paying a second mortgage on a construction loan for a structure that couldn’t be completed.
I spent two weeks in their backyard, not as a builder, as a witness. I learned what a shear wall actually does by watching a framer explain why the original design couldn’t stand. I learned what a hold-down looks like when it’s installed wrong, and what it looks like when it’s right. The daughter, eventually, got her unit, but only after a complete redesign and a family fight that left scars.
I started Ellery because I never wanted to be a witness again. I wanted to be the person who prevents it. The parent company had the model, the Haven Standard was already written, and I brought it to Corona because this is where I live, where I grocery shop, where I see the same faces at the Dos Lagos farmers market. If I screw up here, I don’t lose a customer. I lose a neighbor.
What gets me out of bed is the permit set. Sounds strange, but it’s true. The moment when the city planner stamps the drawings and we know, with evidence, that what’s on paper can actually be built. That stamp means the price we named is the price we’ll deliver. Without it, we’re all guessing. With it, we’re accountable.
If I weren’t doing this, I’d probably be restoring old boats. My grandfather had a fiberglass hull in our garage for most of my childhood, never finished, always promising. The smell of resin and the patience of fairing a curve, that’s the same part of my brain that enjoys getting a foundation square to a sixteenth. But boats don’t need permits, and I need the part where someone else checks my work.
Meet Nadia Ellery - The Person Behind Every Job
Nadia Ellery, Owner and Founder of Ellery ADU Studio Corona. I lead the local branch of a design-build studio that has completed more than 900 ADUs since 2015, every one with a written price before groundbreaking and a documented record at completion.
My training came through the permit expeditor’s path, not the contractor’s license route, which means I read plans before I ever swung a hammer. That sequence matters. I can spot a shear wall conflict in a foundation layout because I’ve sat in the planning department while a planner explained why it wouldn’t pass. I hold the state license required for the work we perform, and every professional working under our name is required to hold the license and insurance their trade demands.
What separates me from a corporate technician is simple: I live in the service area. My truck gets serviced at the same shops yours does. I know which Corona neighborhoods have clay soil that shifts foundations, which ones have HOAs that require specific siding profiles, and which planning staff will return a call by Tuesday versus Thursday.
On weekends, I restore mid-century furniture, badly and slowly. The patience required to strip veneer without destroying the substrate is the same patience I bring to a change order conversation. I don’t rush. I don’t upsell. I document what we found, show you the photo, and let the evidence speak.
My commitment to every customer is personal. Your ADU will be permitted, built, and finished to the drawings, under The Haven Standard, Clause 1 through Clause 5. If it’s not, you have my direct line. Not a queue. Not a ticket. Me.
Before
AfterOur Promise to Corona Homeowners
Honest pricing means we name the range on the page, in dollars, before you call. Our free written estimate breaks every line item, labor and materials separated, so you can verify our math against any other bid. We learned this from the Sierra Del Oro job, the one with the red-tagged foundation. That homeowner never got a written scope. We won’t start without one.
Quality parts means we specify the manufacturer on every material in your contract. James Hardie siding, not “cement board, contractor’s choice.” Plant Prefab or Boxabl units when the design fits modular delivery, with the factory warranty transferred to your name. We document the lot numbers. You get the paperwork.
Standing behind every job means Haven Standard Clause 5: no surprises, and the warranty is in writing before we break ground. We’ve seen the alternative, the handshake promise that evaporates when the principal’s phone goes to voicemail. Our warranty lives in your project folder, with photos, with readings, with the inspector’s sign-off sheet. Evidence on every job, Clause 4. That’s not marketing. That’s the minimum standard for working in someone’s home.
Our Credentials
- State-licensed - We hold the California contractor license required for the scope of work we perform. The license number is available on request and verified with the CSLB before any contract is signed.
- Insured & bonded - Every professional working under our name is required to carry the general liability and workers’ compensation coverage their trade demands, with policy documentation available for your review.
- Years of local experience - Our Corona branch has served this market since 2015, through the full arc of California’s ADU law changes, the 2017 and 2020 code updates, and the post-pandemic permit surge.
- Strong local reputation - We are independently owned and operated, with local crews, local trucks, and local knowledge of Corona’s planning staff, inspection schedules, and neighborhood-specific conditions.
These credentials matter because an ADU is a six-figure project that lives in your backyard for decades. A homeowner hiring someone to work in their home needs more than a friendly voice. They need proof that the person standing in their driveway can be found, can be sued, and has been around long enough that their previous customers still live nearby. Our license and insurance aren’t credentials we display for pride. They’re the minimum barrier to entry for someone who will pour concrete ten feet from your bedroom window. We don’t think that’s optional.
Rooted in Corona
We opened this branch in 2015 because Corona was already changing, the old citrus groves giving way to the infill lots where ADUs make financial sense. We’ve worked in Sierra Del Oro, in the older neighborhoods near Corona High, in the newer developments south of the 91 where the lots are wide enough for a two-bedroom unit without variances. We know which streets flood in January storms, which have HOA architectural committees that meet on Thursdays, and which planning staff will flag a setback before you pay for drawings.
Our crews live here. They buy breakfast at the same places you do. When we promise a real arrival window with a text when we’re on the way, Haven Standard Clause 2, it’s because we know the traffic patterns on Magnolia at 8 AM, not because an app told us. This is our market. We’re not visiting from somewhere else.
Written by Nadia Ellery, Owner at Ellery ADU Studio Corona, serving Corona, El Cerrito, Home Gardens, Norco, El Sobrante, Eastvale, Mira Loma, Temescal Valley, Chino, Pedley, Chino Hills, and Riverside since 2015.