ADU Design & Permitting Near You in Rancho Cucamonga, CA
If you’re searching for our ADU Design & Permitting services near you, Ellery ADU Studio is based in Rancho Cucamonga and covers the Inland Empire’s west end – Upland, Ontario, Fontana, Claremont, Montclair, and the surrounding communities. Every project starts with a written price before any work begins, drawings through final inspection, under one contract. Call (909) 506-1121 and a live person picks up – no voicemail queue.
Ellery ADU Studio has designed, permitted, and built more than 900 ADUs since 2015, every one of them quoted in writing before the first drawing was started. That’s not a policy we invented last year – it’s Haven Standard Clause 1, and it’s been on every contract we’ve signed. If you already have a written estimate from someone else, we’ll give you a Free Second Opinion at no charge, so you know exactly what you’re comparing.
Nadia Ellery leads the studio. The work spans ADU Design & Permitting in Rancho Cucamonga through garage conversions, new detached units, junior ADUs, and site prep – all under a single contract at a single written price. No designer-versus-builder blame gap, because there’s only one party responsible for the outcome.
Fast, Local ADU Design & Permitting
Rancho Cucamonga homeowners typically wait weeks to get a first meeting with a designer who then hands the project off to a separate contractor. At Ellery ADU Studio, the design team and the build crew operate under the same contract from day one. That structure cuts a meaningful amount of time off the schedule because nobody is waiting for the other firm to finish their piece before the next phase can start.
A live person answers at (909) 506-1121 around the clock – if you call at 9 p.m. on a Thursday because you just got a denial letter from the City of Rancho Cucamonga’s building department, someone picks up. We cover Rancho Cucamonga and the surrounding Inland Empire communities, and initial consultations can typically be scheduled within a few business days. The written price you receive at that consultation is the price. Haven Standard Clause 1 locks it before work starts.
Areas We Cover
Ellery ADU Studio is rooted in Rancho Cucamonga and regularly works across the west Inland Empire. HOA & Zoning Compliance, permit requirements, setback rules, and utility connection standards differ city by city – what the City of Rancho Cucamonga’s planning department requires for a rear-yard detached ADU is not the same as what Ontario or Upland requires. We know those differences because we’ve pulled permits in each of these jurisdictions, not because we read the municipal code once.
Service coverage includes:
- Rancho Cucamonga – our home base, including Alta Loma, Etiwanda, and the Vineyard Avenue corridor
- Upland – where older R-1 lots frequently support detached ADUs but require careful attention to existing nonconforming structures
- Ontario – active permit desk, strong demand for garage conversion ADUs near the logistics employment corridor
- Fontana – larger lot inventory in the north end supports new detached units; south Fontana has its own setback nuances
- Montclair – smaller city, faster permit cycles when the application is complete on first submission
- Claremont – historic overlay zones apply in portions of the city and affect exterior materials specifications
- Glen Avon – unincorporated San Bernardino County jurisdiction; county planning rules apply, not a city permit desk
- Mira Loma – also unincorporated Riverside County; a different permit pathway than most clients expect
If your address falls in one of the unincorporated county pockets – Glen Avon or Mira Loma, for example – the permitting path runs through the county planning department, not a city building desk. That distinction changes the timeline and the application package. We’ve navigated both, and the written price you receive will reflect whichever jurisdiction your property sits in.
The full picture of how we approach the permit set and the design process in Rancho Cucamonga is covered on our home page, including the documentation each client receives at every project milestone.
Before
AfterWhat a “Near Me” Search Actually Gets You Here
Most searches for “ADU design and permitting near me” in Rancho Cucamonga surface a mix of architects who don’t build, contractors who don’t draw, and permit expediters who do neither. The result is a three-party project where nobody owns the outcome end to end.
Ellery ADU Studio is structured differently. Design, permit set, and construction are one contract. If the finished ADU isn’t built to the permitted drawings, the 365-Day Done Right Promise – backed in writing before the project starts – requires us to make it right. That promise isn’t a marketing phrase; it’s a clause in the contract you sign at the start. Clients in Rancho Cucamonga and across the Inland Empire receive a documented photo record at each project milestone, so the evidence of what was done is on file, not just in someone’s memory.
For homeowners who want to incorporate a prefab or modular system – Abodu, Cover, Dvele, Mighty Buildings, Boxabl, Plant Prefab, Tuff Shed, or James Hardie panel systems – Ellery specifies and coordinates those within the same single contract. The permit set accounts for the manufacturer’s documentation from the beginning, which avoids the correction letters that slow down prefab projects when a separate designer isn’t familiar with those systems.
ADU Design & Permitting Costs Near Rancho Cucamonga
Written upfront pricing is Haven Standard Clause 1. The ranges below reflect what Ellery ADU Studio has quoted on actual projects in Rancho Cucamonga and the surrounding Inland Empire since 2015. Your written quote will be specific to your parcel, your existing structures, and the jurisdiction your address sits in.
| ADU Type | Typical All-In Range (Design, Permit, Build) | Notes |
|---|---|---|
| Junior ADU (interior conversion, under 500 sq ft) | $80,000 – $130,000 | Existing structure; lower site prep cost |
| Garage Conversion ADU | $110,000 – $175,000 | Slab condition affects range; Rancho Cucamonga requires Title 24 compliance |
| New Detached ADU (up to 850 sq ft) | $175,000 – $280,000 | Utility lateral costs vary by distance from main; Etiwanda lots often run higher |
| New Detached ADU (851 – 1,200 sq ft) | $240,000 – $380,000 | Larger units require more structural engineering; Alta Loma slope lots add cost |
| Prefab / Modular ADU (coordinated) | $160,000 – $310,000 | Manufacturer lead times and site prep are the primary variables |
These are all-in figures: drawings, structural calculations, Title 24 energy compliance report, permit fees paid, and construction through final inspection. Rancho Cucamonga’s building permit fees for ADUs currently run in the $8,000 – $14,000 range depending on square footage and project type – those fees are included in your written quote, not added at the end.
If a number on this table doesn’t match a quote you’ve already received, call (909) 506-1121 and ask for the Free Second Opinion. We’ll look at the written estimate you have and tell you specifically what’s included, what’s missing, and where the difference comes from.
Key Takeaways
- Ellery ADU Studio is based in Rancho Cucamonga and covers Upland, Ontario, Fontana, Montclair, Claremont, Glen Avon, Mira Loma, and surrounding areas.
- Design, permitting, and construction are one contract at one written price – Haven Standard Clause 1, on every project since 2015.
- Over 900 ADUs permitted and built; every project included a documented photo record and a written price before work started.
- The 365-Day Done Right Promise is in writing before your project starts, not offered after a complaint.
- Prefab and modular coordination (Abodu, Cover, Dvele, Mighty Buildings, and others) is within scope of the single contract.
- Unincorporated county parcels in Glen Avon and Mira Loma follow county permit pathways – Ellery has navigated both.
- A live person answers at (909) 506-1121 around the clock.
Frequently Asked Questions
How quickly can Ellery ADU Studio start on my project in Rancho Cucamonga?
Initial consultations in Rancho Cucamonga are typically available within a few business days of your call, and the written price is delivered at that first meeting – not days later. The design phase for a standard garage conversion or detached ADU in Rancho Cucamonga runs roughly 6 to 10 weeks through a complete permit-ready set, depending on the complexity of your site. City of Rancho Cucamonga building department review times for Permit Application submissions have been running 4 to 8 weeks for complete, first-submission packages. Projects submitted with incomplete documentation take longer, which is why we treat the permit set as the core product rather than an administrative step. Call (909) 506-1121 and we can give you a more specific schedule estimate based on your parcel address.
Do you serve my area if I’m not in Rancho Cucamonga?
Yes – Ellery ADU Studio covers Upland, Fontana, Ontario, Montclair, Claremont, Glen Avon, and Mira Loma in addition to Rancho Cucamonga. If your property sits in unincorporated San Bernardino County (Glen Avon) or unincorporated Riverside County (Mira Loma), the permit application goes to the county planning department rather than a city building desk – and the package requirements are different. Your written quote will reflect the actual jurisdiction your address falls in. Call (909) 506-1121 with your street address and we can confirm coverage and the applicable permit pathway in the same call.
What does ADU design and permitting cost near Rancho Cucamonga?
All-in costs for ADU projects near Rancho Cucamonga – drawings, permit fees, structural engineering, Title 24 report, and construction through final inspection – typically run $80,000 to $380,000 depending on ADU type and size. A junior ADU interior conversion generally falls between $80,000 and $130,000. A garage conversion ADU runs $110,000 to $175,000. A new detached ADU of 850 square feet or less typically lands between $175,000 and $280,000. Rancho Cucamonga permit fees alone run $8,000 to $14,000 and are included in the written quote under Haven Standard Clause 1 – not added later. Call (909) 506-1121 for your written project quote; the number you receive at that consultation is the number.
Can I reach someone after hours if I have an urgent permitting question?
A live person answers at (909) 506-1121 around the clock – no voicemail queue, no next-business-day callback. If you’ve received a correction letter from Rancho Cucamonga’s building department at 7 p.m., or if you’re reviewing a contractor’s proposal late and want a second opinion before you sign, you can call that number and reach someone who can help. After-hours calls don’t go to an answering service with a script – they go to someone who knows the projects and the permit process.
Ready to Talk About Your ADU Project Near Rancho Cucamonga?
Ellery ADU Studio serves Rancho Cucamonga and the surrounding Inland Empire communities under one design-build contract at one written price. Nadia Ellery and the team have been doing this since 2015 – more than 900 projects, every one documented, every one quoted in writing before work started. Call (909) 506-1121 today to schedule your consultation and receive your written project price. If you already have an estimate from another firm, ask about the Free Second Opinion – we’ll review what you have and tell you exactly what the numbers mean.
Written by Nadia Ellery, Owner at Ellery ADU Studio Rancho Cucamonga, serving Rancho Cucamonga and nearby areas.
What Our Customers Say
"Every allowance was itemised at the start, so the finish selections did not turn into a surprise at the end."
- Benedict H."Detached unit in the back garden. Good design, good build quality, and the cost changes were documented and agreed in advance."
- Stefan B."They walked us through setbacks and utility capacity before we paid anything, and told us one of our two options was not going to get approved."
- Mireille T.