The Ellery ADU Studio Diamond Bar Guarantee
We’re Nadia Ellery and the team at Ellery ADU Studio Diamond Bar. Since 2015, we’ve designed, permitted, and built more than 900 ADUs across Southern California, and every single one started with a written price and ended with a documented photo record. Our guarantee isn’t a feel-good tagline. It’s a set of clauses in every contract that tell you exactly what we’ll do, what you’ll pay, and what happens if something isn’t right. In Diamond Bar, where permit timelines run long and construction costs sting, that specificity matters more than reassurance ever could.
What’s Covered
- Workmanship to the permitted drawings. We build what was approved by the city of Diamond Bar, not what was easier that week. Under our 365-Day Done Right Promise, if the finished ADU doesn’t match the permitted set, we make it right - in writing, before your project starts, not as a negotiation after.
- Written price before any work starts. Haven Standard Clause 1 applies to every project we take in Diamond Bar. You’ll see a line-item quote covering design, permitting, construction, and site prep before you sign. The words “call for a quote” don’t appear anywhere in our process because they shouldn’t appear in yours.
- Documented photo record on every visit. Our crews photograph what they find and what they do - foundation conditions, existing slab thickness, utility tie-in points, framing progress. You receive the images, not a summary of how it felt to be there. When Diamond Bar’s building inspector asks about a specific inspection hold, you’ll have dated evidence.
- No scope creep, no door-side upsells. Haven Standard Clause 5 (No Surprises) locks the scope at signing. If we missed a condition during our site evaluation, that’s our error to absorb - not yours to discover halfway through construction.
- Background-checked, uniformed crews with visible credentials. Every technician who steps onto your Diamond Bar property carries a license number you can verify. We don’t claim “licensed and insured” and hope you don’t ask. The number appears on every page of our documentation.
- Cleanup that respects your existing home. ADU construction happens in your backyard, often for months. We haul debris on schedule, protect access paths, and leave the site workable between phases. Your main house isn’t a storage shed for our materials.
- On-time permit submission and inspection scheduling. Diamond Bar’s Community Development Department has specific submittal requirements and inspection windows. We know them because we’ve worked with them since 2015. Delays happen, but they don’t happen because we submitted the wrong fire separation detail or called for inspection out of sequence.
- Honest prefab and modular coordination. We specify and coordinate systems from Abodu, Cover, Dvele, Mighty Buildings, Boxabl, Plant Prefab, Tuff Shed, and James Hardie under the same single contract. If a prefab unit arrives with a dimensional variance that affects your Diamond Bar setback compliance, we catch it before the crane shows up - not after.
Our Satisfaction Promise
If something isn’t right, we don’t wait for you to escalate. Here’s how the make-it-right process works at Ellery ADU Studio Diamond Bar.
First, you tell us - by phone, by email, or by flagging the issue in your photo record. A live person answers calls 24/7, so you’re not leaving a voicemail that disappears into a callback queue. Second, we verify. We pull the permit set, the written scope, and the dated photos from the visit in question. We tell you what we found, not what we felt. “The shear wall nailing pattern in bay three is 6 inches on center, not 4 inches as specified. Here’s the photo from March 14th showing the spacing before drywall went up.” Third, we fix it. Under the 365-Day Done Right Promise, if the finished ADU isn’t built to the permitted drawings, we correct the defect at our cost. No deductibles, no “normal wear and tear” exclusions, no pointing at a subcontractor who no longer returns calls. The promise is backed in writing before your project starts because a six-figure decision deserves that level of clarity.
We’ve honored this process on projects where the issue was ours - a misread dimension on a foundation plan, a window spec that didn’t match the energy compliance report. We’ve also honored it when the issue was murkier, when the city’s interpretation shifted mid-project or when a supplier changed a standard detail without notice. The Haven Standard doesn’t have a “unless it’s complicated” escape hatch.
Licensed & Insured Backing
Licensing and insurance aren’t marketing badges. They’re the mechanism that makes every other promise enforceable. Our state license means we’ve met California’s examination, experience, and bond requirements for the work we perform in Diamond Bar. Our insurance and bonding means that if a catastrophic error occurred - a foundation failure, a fire separation breach, a worker injury on your property - there’s a financial backstop that doesn’t depend on our personal goodwill or your homeowner’s policy.
We’ve seen what happens when unlicensed operators take on ADU work in Diamond Bar. Permits get abandoned mid-process. Lien claims surface from unpaid material suppliers. Homeowners discover their “contractor” was a salesperson who subcontracted to an unverified crew. Our license number on every page of our documentation isn’t vanity. It’s traceability. You can verify it with the Contractors State License Board. You can verify our insurance certificate. You can’t verify a handshake.
The Haven Standard exists because Nadia Ellery built this studio after watching too many Diamond Bar homeowners get stranded between a designer who blamed the builder and a builder who blamed the designer. One contract, one written price, one party responsible for making it right. That’s the guarantee.
Free Second Opinion
If you already have a written estimate for an ADU project in Diamond Bar - from another design-build studio, from a separate architect and contractor, from a prefab company selling direct - we’ll review it at no charge. We’ll tell you what’s clear, what’s vague, and what’s missing. We’ve caught scope gaps that would have cost homeowners $40,000 in change orders, and we’ve confirmed estimates that were fairly priced. Either way, you leave with better information than you came with. Call (657) 239-4865 to schedule your free second opinion.
Common Questions About Our Guarantee
What does the 365-Day Done Right Promise actually cover?
It covers conformance to the permitted drawings and the written scope of work. If the finished ADU in Diamond Bar deviates from what was approved by the city and agreed to in your contract, we correct it at our expense. This is not a manufacturer’s warranty on appliances or fixtures - those come from their respective makers. It’s a workmanship and compliance guarantee on the structure we built. Call (657) 239-4865 and we’ll walk through exactly how this applies to your project type.
Will the price I sign change once work starts?
No. Haven Standard Clause 1 requires a written price before any work begins, and Clause 5 locks the scope at signing. The only way your price changes is if you request a change order in writing, or if a concealed condition emerges that no reasonable site evaluation could have detected - and even then, we document it with photos and discuss options before proceeding. Call (657) 239-4865 for an exact quote on your Diamond Bar property - estimates are free.
What documentation do I receive?
You receive the permit set approved by Diamond Bar Community Development, a written scope with line-item pricing, dated photo records from every site visit, and the 365-Day Done Right Promise in writing before construction begins. After completion, you receive final inspection sign-offs and photographic as-builts showing key systems access points. These aren’t summaries of how the work felt. They’re evidence of what was done.
How do I know your crews are actually background-checked and licensed?
Our license number appears on every page of our project documentation. You can verify it with the CSLB. Crew members wear uniforms with visible identification, and our project managers carry credentials you can photograph. We don’t ask for trust on this point. We make verification trivial.
What happens if I need help after hours?
A live person answers calls 24/7. Not a voicemail queue. Not a callback promise that doesn’t materialize. If you have an urgent concern about your active Diamond Bar project - a safety issue, an access dispute with a neighbor, a sudden weather exposure - you’ll reach someone who can dispatch or escalate. Call (657) 239-4865.
Written by Nadia Ellery, Owner at Ellery ADU Studio Diamond Bar, serving Diamond Bar since 2015.