Fast, Reliable New Detached ADU Across Dublin
A new detached ADU in Dublin runs $280,000-$420,000 all-in, drawings through final inspection, depending on square footage, site access, and whether your lot carries county septic or well overlays. Most detached builds in Dublin take 10-16 months from the first survey to the certificate of occupancy. That’s the number you need to start your planning, and we put it in writing before any work begins. Call (971) 497-2402 to schedule a free site walk and get a written scope for your Dublin property.

We know Dublin’s master-planned subdivisions street by street, from Jordan Ranch to Positano to Sorrento, and we know which lots still answer to Alameda County for septic and well clearance. That local knowledge changes what gets scoped, what gets permitted, and what clears final inspection on the first pass. Our team works in Dublin every week, and we schedule site walks within days, not weeks.
Why Ellery ADU Studio Is Dublin’s Preferred New Detached ADU Company
Ellery ADU Studio has designed, permitted, and built over 900 ADUs since 2015, and a meaningful share of those are detached units in Dublin’s HOA-governed subdivisions. Dublin homeowners call us because we already know the dual-approval gauntlet: City of Dublin building permits plus HOA architectural committee review. We know which HOAs want matching stucco reveals, which ones restrict roof pitch, and which ones will bounce a plan for a window style that doesn’t match the production builder’s original spec.
Our Dublin clients get a documented photo record on every visit, a written price before work starts under Haven Standard Clause 1, and a 365-Day Done Right Promise: if the finished ADU is not built to the permitted drawings, we make it right, in writing, before the project starts. We’re led by Nadia Ellery, who founded the studio in 2015, the year California’s ADU permitting landscape shifted. Nadia’s name is on every Dublin permit set that leaves our office.
One contract covers the drawings, the permit set, and the construction. No designer-versus-builder blame gap. No “call for a quote” runaround. You get a line-item written price, and we lock the scope at signing under Clause 5 (No Surprises). A live person answers our phones 24/7, so when you call at 9pm to ask about a setback question, you get Nadia or a member of our team, not a voicemail.
Our New Detached ADU Services in Dublin

Custom Built ADU
Custom detached ADUs in Dublin typically run $320,000-$420,000 for a 600-1,000 sq ft unit built on-site. Your Dublin lot’s constraints drive the design: east-side parcels with county septic overlays need setback clearances that most stock plans ignore, and HOA exterior standards in Jordan Ranch or Sorrento can dictate cladding, roof tile color, and even fascia profiles. We draft the permit set around those constraints from day one, so the unit clears architectural review and building inspection without a re-clad order.

1-Bed & 2-Bed ADU
A one-bedroom detached ADU in Dublin runs $280,000-$340,000; a two-bedroom runs $360,000-$450,000. The two-bedroom price climbs faster in Dublin because many production-built lots from Shea, Toll Brothers, and Pulte have narrow side yards, which means a two-bedroom footprint pushes into rear-yard setback territory faster, and east-side lots may trigger a septic tank setback review that a one-bedroom never touches. We scope both scenarios before quoting, so your written price reflects your actual lot, not a template.

Studio ADU
Studio detached ADUs in Dublin run $220,000-$290,000. A studio’s smaller footprint often fits within standard Dublin rear-yard setbacks without a variance request, which shortens the permit timeline by several weeks. But don’t assume the finish work is simple: Dublin production slabs routinely lack interior drains and conduit stub-outs, so even a studio conversion of a detached garage means cutting the slab for the plumbing rough-in. We include that line item in the written scope, not as a change order later.

Prefab ADU Installation
We specify and coordinate prefab and modular systems from Cover, Dvele, and Abodu for Dublin clients who want factory-built precision with local site work handled under one contract. A Cover or Dvele unit on a Dublin lot typically runs $250,000-$380,000 delivered, set, and finished, including the foundation, utility connections, and the HOA-facing exterior adjustments. We coordinate the entire system within the same single contract, so there’s no gap between the factory’s spec and the city’s inspection requirements.

What happens when you call
- 1
A real person answersNo phone trees - you reach a local pro.
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You get an upfront price rangeHonest numbers before anyone is dispatched.
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A background-checked tech heads outLicensed & insured, dispatched right away.
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You approve before work beginsNothing starts until you say go.
Trusted Brands We Service in Dublin
We work with prefab and modular systems from Cover, Dvele, and Abodu, among others, and we know how those systems interact with Dublin’s HOA exterior standards and the county’s septic and well overlays on east-side lots. When a Cover unit’s standard cladding conflicts with a Positano HOA color palette, we don’t guess; we coordinate the substitution before the module ships. We stock common connection parts locally for Dublin installs, so site work doesn’t stall waiting on a factory shipment from out of state. Our crews are background-checked and uniformed, and our license number appears on every page and every contract.

Common New Detached ADU Problems We See in Dublin Homes

- Assuming city-only permitting on east-side lots. Dublin’s east side, out toward the San Ramon line, still carries rural Alameda County utility overlays from before annexation. Missing the county septic and well clearance stalls final inspection for weeks, and it’s the single most common thing we catch on existing plans from out-of-area builders.
- Undersized mini-splits on low-slope roofs. Dublin hits 95-105°F during summer heat events, 20-30 degrees hotter than the Fremont or Oakland coastline. A unit sized on coastal assumptions faults out by July, and we see this diagnostic pattern on nearly every existing garage conversion we’re asked to repair.
- Bidding from a stock plan without checking HOA exterior standards. Jordan Ranch and Sorrento HOAs enforce approved color palettes and matching materials. A stock plan’s default siding can force a full re-clad after the fact, adding $12,000-$18,000 and six weeks to a job that was already underway. We check HOA architectural guidelines before we draw.
- Production-built slabs without interior drains. Shea, Toll Brothers, and Pulte poured Dublin’s garage slabs without interior drains or conduit stub-outs, as standard practice on their production lines. A detached ADU conversion almost always requires cutting the slab to add plumbing rough-in and a cleanout, and a contractor who didn’t scope it will hit you with a change order mid-job.
Pricing for New Detached ADU in Dublin, CA
Here are the ranges we quote for Dublin detached ADUs, all-in from drawings through final inspection:
- Studio ADU (400-600 sq ft): $220,000-$290,000
- 1-Bedroom ADU (500-750 sq ft): $280,000-$340,000
- 2-Bedroom ADU (750-1,000 sq ft): $360,000-$450,000
- Prefab ADU (Cover, Dvele, Abodu): $250,000-$380,000 including site work, foundation, and utility connections
- Slab cutting for plumbing rough-in: $4,000-$9,000 depending on line depth and cleanout placement
- HOA architectural review support and resubmission: included in our fixed scope, never billed as a separate line item
Every quote is a written line-item price under Haven Standard Clause 1, so the number on the page is the number on the contract. We don’t bid low and change-order our way up. If you already have a written estimate from another builder, call (971) 497-2402 and ask for our Free Second Opinion; we’ll walk through the scope with you and point out what’s missing, what’s double-counted, and what won’t clear Dublin inspection.
We Also Serve Cities Near Dublin

Our team regularly serves Dublin and the surrounding Tri-Valley corridor, including Hayward, San Ramon, Pleasanton, and Danville. If you’re in a neighboring city and comparing written estimates, the same Haven Standard applies: written price before work starts, documented photo record on every visit, and a 365-Day Done Right Promise. Our New Detached ADU work spans the region, but this page’s pricing and permitting notes are specific to Dublin’s HOA and county-overlay conditions.
Serving Dublin, CA - Our Local Coverage Area
We’re based in the Dublin area and know this community well. Use the map below to see our service coverage - if you’re nearby, we can almost certainly help.
FAQs - New Detached ADU in Dublin

Dublin’s HOA architectural review adds 3-8 weeks to the front end of a detached ADU project, on top of the City of Dublin building permit review. The HOAs in Jordan Ranch, Positano, Sorrento, and Waterford each have their own exterior standards, and we submit the architectural package to the HOA at the same time we file with the city, so the two reviews run in parallel rather than serial. Missing this step, or submitting a stock plan that doesn’t match the HOA’s approved color palette, is the fastest way to add a month and a re-clad budget line. Call (971) 497-2402 and we’ll check your specific HOA’s guidelines before you commit to a design.
Yes, if your lot is on Dublin’s east side, out toward San Ramon, where rural Alameda County utility overlays still apply even inside city limits. The county requires septic tank and well setback clearances measured from any new detached structure, and that analysis has to be filed before the city will issue a final inspection. We scope it in the written quote from the start; if a previous builder’s estimate doesn’t mention it, that’s a red flag. Call (971) 497-2402 for a site walk and we’ll tell you definitively whether your lot carries the overlay.
Because virtually every Dublin subdivision was built by large production builders like Shea, Toll Brothers, and Pulte, and those builders poured garage slabs without interior drains or conduit stub-outs as a cost-saving standard. Adding a bathroom, kitchen, or laundry to a detached structure means cutting the slab to run plumbing rough-in and install a cleanout, and that’s a line item we include in the written scope before you sign. Contractors who omit it are planning to change-order you after demolition. Call (971) 497-2402 and we’ll walk your lot and show you exactly where the slab work lands in your quote.
Yes, and we coordinate those systems under one contract so the HOA’s exterior standards are addressed before the module is ever ordered. Cover and Dvele units are fully permitted in Dublin, but the HOA may require specific cladding, window trim, or roof profiles that differ from the factory’s default spec. We handle that coordination, the foundation, the utility connections, and the written price, so the factory’s scope and the HOA’s scope don’t conflict. Call (971) 497-2402 for a written quote on a prefab unit for your specific Dublin lot.
Dublin’s summer heat events push 95-105°F, and a detached unit with a low-slope roof and no shade gains 20-30 degrees more than the same unit would in Fremont or Oakland. The mini-split has to be sized for that inland thermal load, not the coastal assumptions that come baked into many prefab and stock-plan specs. We specify the equipment for Dublin’s actual summer conditions, and we include the load calculation in your permit set so the inspector sees the math. Call (971) 497-2402 and we’ll run the numbers for your lot’s orientation and roof profile.
Key Takeaways
- A new detached ADU in Dublin runs $220,000-$450,000 all-in, depending on size, site access, and whether your lot carries county septic or well overlays.
- Dublin’s HOA dual-approval process adds 3-8 weeks, and we file both reviews in parallel to keep the timeline moving.
- East-side Dublin lots often require county septic and well setback analysis even inside city limits, a step most out-of-area builders miss.
- Production-built Dublin slabs lack interior drains, so slab cutting for plumbing rough-in is a standard scope item, not a surprise.
- Every project gets a written line-item price before work starts, a documented photo record on every visit, and a 365-Day Done Right Promise under The Haven Standard.
Get a Written Price for Your Dublin Detached ADU

We build detached ADUs in Dublin on acreage, on standard subdivision lots, and on east-side parcels with rural county overlays. On a lot off Dublin Boulevard out toward San Ramon, our crew converted a former Shea-built home’s oversized side yard into a detached two-bedroom ADU. We ran our survey crew twice after a Positano HOA architectural review flagged a stucco reveal mismatch, and the final scope included cutting the existing garage slab to add a cleanout because there was no interior drain stub-out. That’s the kind of site-specific scoping you get when you work with a team that knows Dublin’s production-slab and HOA conditions, not a template.
Call (971) 497-2402 to schedule your free site walk and get a written price for your Dublin detached ADU. A live person answers, and you’ll get a line-item scope under Haven Standard Clause 1 before any work begins.
Written by Nadia Ellery, Owner at Ellery ADU Studio, serving Dublin since 2015 with a documented photo record on every project.