Frequently Asked Questions - ADU in San Bernardino, CA
We've been designing and building ADUs across San Bernardino County since 2015. Here are the questions we actually get, answered directly.
Pricing & Cost FAQs
Most attached and detached ADUs we quote in San Bernardino fall between $180,000 and $350,000 all-in, depending on size, foundation type, and utility connections. A 400-square-foot garage conversion typically lands at the lower end, while a 1,200-square-foot detached new build with full kitchen and separate meter runs higher. We quote in writing before anyone starts - that's Clause 1 of our Haven Standard. Call (909) 359-6463 for a free written estimate with line-item pricing.
No. Our contract price is fixed unless you change the scope. We build that price from a completed permit set and a site visit, not from guesswork. If we hit unexpected soil conditions or a buried utility, we document it with photos and readings (Clause 4 of the Haven Standard) and quote the change in writing before proceeding. No surprises means no surprises. Call (909) 359-6463 to schedule your free estimate.
Most of our clients use HELOCs, cash-out refinances, or California's CalHFA ADU Grant program, which offers up to $40,000 for pre-development costs. Some lenders in the Inland Empire now offer ADU-specific construction loans. We don't originate loans, but we provide the written quote and permit documentation your lender will need. Call (909) 359-6463 and we'll point you toward lenders who've funded our projects before.
Permits, utility connections, and impact fees are included in our written quote - never hidden. San Bernardino's ADU permit fees typically run $8,000-$15,000 depending on square footage and whether you're creating a new meter. SCE connection costs for a separate electric service can add $3,000-$8,000 if trenching is required. We itemize these in your estimate so you see where every dollar goes.
Service & Process FAQs
From signed contract to certificate of occupancy, most of our San Bernardino ADUs take 8 to 14 months. Design and permitting typically consume 3 to 5 months - San Bernardino County's planning department has improved turnaround but still reviews ADU plans in 6 to 10 weeks. Construction runs 4 to 6 months for a garage conversion, 6 to 9 months for detached new construction. We give you a real schedule with named milestones, not a wish. Call (909) 359-6463 for a timeline based on your specific site.
A design-build studio holds one contract for both the drawings and the construction. With a traditional contractor, you hire an architect separately, then bid the plans to builders - and when the as-built conditions don't match the drawings, each side blames the other. We've seen that movie. Since 2015, we've handled both under one fixed price because the ADU projects that fail are almost always the ones where designer and builder were different companies with different incentives.
Yes. We pull the permit, we meet the inspector, we correct any notes. Our permit set includes structural calcs, Title 24 energy compliance, and San Bernardino County's specific fire separation requirements for attached units. You receive copies of every approved plan, every inspection sign-off, and the final certificate of occupancy. Documentation is Clause 4 of the Haven Standard - evidence of what we actually built.
Yes, garage conversions are about 40% of our San Bernardino work. The existing slab, walls, and roof structure often save significant cost versus new construction, but we still need to verify the foundation meets current seismic standards and that ceiling height clears 7'6" after insulation and finishes. We assess this in our initial site visit and tell you exactly what the conversion requires versus starting fresh.
Yes. We serve the full San Bernardino Valley including Rialto, Colton, Grand Terrace, Highland, Redlands, Fontana, and west to Riverside, Rancho Cucamonga, Moreno Valley, Yucaipa, and Hesperia. Each city has slightly different setback rules and utility connection requirements - our permit team knows which inspector in Rancho Cucamonga wants fire-rated drywall at the property line, and which Colton plans examiner flags certain foundation details. That local knowledge saves weeks.
Brands & Parts FAQs
We work with several prefab manufacturers including Abodu and Mighty Buildings when the site conditions and client timeline favor factory-built modules. Prefab can compress the construction schedule by 2 to 3 months since the unit is built while we handle site prep and foundation. We also design and stick-build on site when the lot is sloped, access is tight, or the design is custom. Your written quote compares both paths honestly.
We've installed Dvele units for clients who wanted their integrated smart-home systems and high-performance envelopes. Cover's panelized approach works well on some San Bernardino infill lots where crane access is limited. We're not exclusive to any manufacturer - we recommend the system that fits your site, budget, and whether you plan to rent the unit or house family. Every option is quoted in writing with the same fixed-price guarantee.
Sometimes, but not always. Factory labor efficiency saves money, but shipping a 14-foot-wide module from the Bay Area or Southern California factory to San Bernardino adds transport cost, and crane rental runs $2,000-$4,000 for a half-day. On flat lots with good access, prefab often wins. On hillside properties in Highland or Yucaipa, site-built is usually more practical. We quote both and let the numbers decide.
Licensing & Insurance FAQs
Every pro working under our name is required to hold the license and insurance California requires for ADU construction - specifically a B-General Building Contractor license for the build phase, and our design team holds architectural credentials where required. We display license numbers on every proposal. Haven's verification system confirms active status and insurance before any crew steps on your property. That's Clause 3 of the Haven Standard.
We carry general liability and workers compensation coverage as required by California law. You receive a certificate of insurance naming you as additional insured before construction begins. This is standard for any significant construction project - if a contractor hesitates to provide it, that's a signal. We provide it automatically with your contract packet.
No. We pull all permits as the responsible party. In San Bernardino County, the property owner can technically act as their own contractor (Owner-Builder), but that makes you personally liable for workers comp, code compliance, and lien exposure. We don't recommend it for ADUs - the permit set is 30+ pages and the inspection sequence has 8 to 12 checkpoints. We handle this daily; you shouldn't need to learn it once.
Emergency & Response FAQs
Contact your project manager directly - you'll have their cell and email from day one. For urgent issues like a water line hit or structural concern discovered during excavation, we respond during our business hours: Monday through Friday 7:30 AM to 8:00 PM, Saturday and Sunday 7:30 AM to 7:00 PM. Our live coordinator routes after-hours emergencies to the on-call manager. We don't promise 24/7 response, but we do promise a human answers during those hours and urgent issues get same-day callback.
We don't market emergency services - ADUs aren't emergency construction. If your completed ADU has a plumbing leak or electrical issue, we coordinate repair through our normal scheduling, typically within 48 to 72 hours. For true emergencies (gas leak, electrical fire risk), call your utility or 911 first, then contact us for the follow-up repair. Our warranty covers defects in workmanship; we'll inspect and fix what's ours.
We're open Monday through Friday 7:30 AM to 8:00 PM, Saturday 7:30 AM to 7:00 PM, and Sunday 7:30 AM to 7:00 PM. Calls are answered by a live coordinator who connects you with the local team - in San Bernardino, that's Nadia Ellery's crew. We don't use automated phone trees for new inquiries, and we don't claim to be available around the clock because that wouldn't be honest.
Warranty & Guarantees FAQs
We provide a written workmanship warranty on every ADU - one year on standard finishes, with extended coverage on structural elements and major systems. The specific terms are spelled out in your contract before anyone starts (Clause 1: Have it in writing). We also pass through all manufacturer warranties on appliances, fixtures, and any prefab unit shell. You'll receive warranty documentation for every covered component, not just a handshake.
Call us. We document every job with photos and readings (Clause 4), so we can verify what we installed versus what changed after occupancy. If it's our workmanship, we fix it. If it's a manufacturer defect, we facilitate the warranty claim. If it's normal settling or maintenance, we'll tell you that too - we say what we found, not what we felt about it. Our reputation in San Bernardino depends on handling the post-move-in phase honestly, not just the sale.
Yes. The price in your signed contract is the price you pay for the scope described, period. The only way it changes is if you change the scope - add a deck, upgrade appliances, move a wall - and even then, we quote the change in writing before proceeding. No surprises is Clause 5 of the Haven Standard. We've built 900+ ADUs since 2015 under this system; the fixed price is the whole reason the system works.
We guarantee we'll submit a complete, code-compliant permit set and shepherd it through review. If San Bernardino County or your specific city requests corrections - common on first submittal - we make them at our cost and resubmit promptly. We don't control the planning department's timeline or their interpretation of discretionary rules, but we do know their reviewers by name and their typical concerns by heart. Most of our permits approve on first or second submittal.
Written by Nadia Ellery, Owner at Ellery ADU Studio San Bernardino, serving San Bernardino, Rialto, Colton, Grand Terrace, Highland, Redlands, Fontana, Riverside, Rancho Cucamonga, Moreno Valley, Yucaipa, and Hesperia since 2015.
Still Have Questions?
We are happy to help. Call us - same-day and after-hours emergency service available.
(909) 359-6463