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(657) 239-4865Diamond Bar, CA 91765
Contact Ellery ADU Studio Diamond Bar - Free ADU Estimate in Diamond Bar
Call (657) 239-4865 to schedule your free ADU estimate in Diamond Bar. When you reach us, a live coordinator will connect you with our local team. There’s no hard sell, no deposit required to get your numbers, and we can usually assess your property within a few business days. We’ll walk your lot, check setback and utility conditions, and email you a written, line-item estimate you can actually compare.
What Happens When You Call
Step 1: We answer and listen. A live coordinator picks up during business hours and connects you with our Diamond Bar team. We’ll ask about your property address, your goals for the ADU, and whether you’re leaning toward a garage conversion, backyard cottage, or prefab unit. This takes ten minutes and costs nothing.
Step 2: We schedule a site assessment. We visit your property in Diamond Bar to measure setbacks, check utility access, and photograph existing conditions. We bring a checklist drawn from 900+ ADU projects since 2015, so we don’t miss the drainage issue or the overhead line that could add eight weeks later.
Step 3: You receive a written estimate. Within 48 hours of the visit, you get a line-item quote: design, permit set, site prep, build, and finish. The Haven Standard, Clause 1, requires the full price in writing before anyone starts. No “allowances” that balloon. No “TBD” on the foundation.
Step 4: We build to the drawings. Once you approve, we pull permits, schedule inspections, and execute the scope we quoted. Clause 4 of The Haven Standard means photo documentation at every phase, and Clause 5 means no surprises - the price we wrote is the price you pay.
Why Diamond Bar Homeowners Call Us First
- We’re local to the San Gabriel Valley. Our team lives and works within 20 minutes of Diamond Bar, which means we understand the specific conditions that affect ADU builds here: the hillside lots off Grand Avenue, the older utility easements in the Country Estates area, and the City of Diamond Bar’s particular requirements for fire separation on garage conversions.
- Every pro on your job carries the license and insurance California requires. We don’t send crews whose paperwork we haven’t verified. License numbers appear on your contract, and certificates of insurance are available on request. This is The Haven Standard, Clause 3.
- The price on the page is the price on the invoice. Our written estimates include every line item from soil testing to final paint. If we missed something, we absorb it. Clause 5 of The Haven Standard - no surprises - is not a slogan; it’s the terms you sign.
- We document everything and we guarantee the work. You’ll receive dated photos of trench depth, rebar placement, and insulation R-value readings. Our workmanship warranty is written into every contract, and because we’re independently owned and operated here in Diamond Bar, you know exactly who stands behind it.
Our Service Area Around Diamond Bar
We design, permit, and build ADUs throughout the eastern San Gabriel Valley and northern Orange County. Typical response times: Diamond Bar and Walnut within 1-2 days; Rowland Heights, Pomona, and Brea within 2-3 days; Chino Hills, Covina, San Dimas, and Chino within 3-4 days; Yorba Linda, Montclair, and Placentia within 4-5 days. If your city isn’t listed, call anyway - we’ve permitted ADUs in unincorporated Los Angeles County and can likely service your area.
Frequently Asked Questions - Booking & Estimates
Yes. The site assessment and written estimate are free with no obligation. We believe you can’t make a six-figure decision without real numbers, so we put them in writing before we ask for anything. Call (657) 239-4865 to schedule yours.
We typically schedule site assessments within 3-5 business days of your call. Our Diamond Bar projects get priority scheduling because our design team and permit runners are already in the area. Call (657) 239-4865 and we’ll find a window that works.
No. Our site assessments happen during daylight hours for accuracy, but we do not surcharge for Saturday or Sunday appointments. Our standard hours are Monday through Friday 7:00 AM to 7:00 PM, and Sunday 7:00 AM to 7:00 PM. We are closed Saturday. Call (657) 239-4865 to check weekend availability.
Your property address, a rough idea of the ADU size or type you’re considering, and whether you’ve checked basic zoning on the City of Diamond Bar website. If you have a survey or plot plan, great, but it’s not required for the initial call. We’ll guide you through what we need. Call (657) 239-4865 to get started.
We accept check, ACH transfer, and major credit cards. For ADU builds, we structure payments to milestones: design approval, permit issuance, foundation completion, framing, and final walkthrough. The schedule is written into your contract under Clause 1. Call (657) 239-4865 to discuss what works for your timeline.
Call or Request a Callback
(657) 239-4865
Monday - Friday: 7:00 AM - 7:00 PM
Sunday: 7:00 AM - 7:00 PM
Saturday: Closed
No pressure, no deposit to get your numbers. Just a written estimate you can take to three other builders if you want. That’s The Haven Standard.
Written by Nadia Ellery, Owner at Ellery ADU Studio Diamond Bar, serving Diamond Bar and the San Gabriel Valley since 2015.