







A free site visit, a check of what your lot allows and a written, line-item price.
Get your free estimateFast, Reliable ADU Builders Across Arcadia
Building an ADU in Arcadia means working through the city’s own Planning and Building counter, not a one-size-fits-all county checklist. That changes what gets bid, what passes plan check, and what the final invoice looks like. Fielding ADU Builders has walked enough Arcadia projects through the municipal review to know exactly where the city draws the line on setbacks, lot coverage, and utility separation. If you’re weighing a detached unit in the rear yard off Camino Real Avenue or a JADU carved out of an existing garage, call (361) 315-4177. We’ll scope it the way Arcadia actually reviews it.
Why Fielding ADU Builders Is Arcadia’s Preferred ADU Builders Company

Arcadia homeowners tend to come to us after a bad first bid. They’ve already heard one contractor quote a number, then watched the number move once plan check came back with comments. We run this differently. The price goes in writing before any work starts, and the number you approve on day one is the number on the final invoice. Reed Calloway, who leads our ADU work, insists on that. No change orders invented at the door.
Our crews show up in uniform, background-checked, and they work under The Garrison Standard. That means a written one-year guarantee on every ADU we build in Arcadia, plus a free second visit if the work fails inside that year. The guarantee is spelled out on paper, not promised over a handshake. We’re part of the Garrison Partners family, which has been building to this standard since 2006.
We also answer the phone. A live person picks up 24 hours a day, 7 days a week. No voicemail queue when you’re trying to figure out whether your lot can even fit a unit under Arcadia’s rear-yard rule.
Detached ADU in Arcadia
A detached ADU in Arcadia is a fully separate dwelling unit built in the rear yard, and it’s the most common way homeowners on larger Arcadia lots add rental income or space for family. Arcadia enforces a single-story pattern for most rear-yard units and a 4-foot side and rear setback, which means the site plan has to be drawn to the city’s specific envelope, not a generic LA County template. We scope every detached project against Arcadia’s municipal review from the first conversation, so the drawings don’t bounce back for redesign.
Scoping for Arcadia’s Plan Check
Before we price a detached ADU in Arcadia, we review the lot’s existing improvements. A rear garage that sits too close to a property line can create a non-conforming setback line, which changes where the new unit can land. We flag that early. It’s cheaper to solve on paper than mid-permit.
Build Method and Cost Range
A conventional detached ADU in Arcadia typically runs $180,000 to $320,000 depending on size, finish, and whether utilities need new trenching. A panelized shell from Plant Prefab or Abodu can tighten framing time, but the foundation, utility trenching, and city inspections still set the critical path. Permits and school fees sit on top of construction costs.
JADU in Arcadia

A JADU, or Junior ADU, is a smaller unit created within the footprint of an existing home, usually from a garage, and Arcadia’s review expects it to function as an independent living space with its own kitchenette, access, and utility separation. That’s the part that gets underbid. A JADU is not a drywall-and-door job. It’s a real dwelling unit with code requirements that Arcadia’s plan check reviews carefully.
What Arcadia Expects in a JADU
Arcadia’s review looks for a separate entrance, a kitchenette with a sink and cooking appliance, and a bathroom that meets current code. Utility separation matters too. If the JADU shares water and power with the main house without separate metering or shutoffs, plan check will send it back. We price those items up front.
Typical JADU Cost in Arcadia
A garage-to-JADU conversion in Arcadia generally runs $85,000 to $150,000 before permit fees. The range depends on whether the garage is attached or detached, whether the slab needs work, and how much utility separation the city requires on that specific lot. We put that number in writing before anything starts.
Trusted Brands We Service in Arcadia
We work with the ADU platforms Arcadia homeowners are already researching. That includes Abodu, Cover, Dvele, and Mighty Buildings for prefab and panelized shells, plus conventional builds using James Hardie siding. When a client wants a specific method, we don’t talk them out of it. We match the build method to the lot and the budget. For Arcadia properties with a tight rear-yard envelope, we’ve used Plant Prefab panelized shells to keep structures single-story and inside the city’s setback line.
Common ADU Builders Problems We See in Arcadia Homes
- Setback math done to a neighboring city’s rules. Arcadia runs its own plan check, and a site plan drawn for Monrovia’s setbacks will get bounced in Arcadia. We see this most often when a homeowner brings in drawings from a contractor who works more in Temple City or San Gabriel.
- JADU bids that skip the kitchenette and utility separation. Arcadia reviews JADUs as independent units. A bid that treats it like a finished storage room won’t survive plan check, and the price moves later.
- Assuming prefab means a faster permit. A panelized shell from Mighty Buildings or Cover can speed framing, but Arcadia’s foundation inspection, utility trenching, and final sign-off still drive the calendar. Anyone promising a dramatically shorter timeline is not being straight about the city’s process.
- Pricing without checking the existing rear-yard improvements. Older Arcadia homes near Camino Real Avenue often have rear garages that sit on non-conforming setbacks. That changes where a detached unit can go, and it needs to be priced before bid day.
Pricing for ADU Builders in Arcadia, CA
Here are honest ranges for Arcadia. A JADU conversion typically runs $85,000 to $150,000. A detached ADU runs $180,000 to $320,000, depending on size and finish. Prefab shells from Abodu, Cover, or Dvele tend to land in the middle to upper part of that range. Conventional builds with James Hardie siding can be priced tighter if the lot is straightforward. Permit fees, school district fees, and utility connection charges are separate line items and we show them as such. The free estimate is how you get an exact number for your specific lot. Call (361) 315-4177 and we’ll put the estimate in writing.
We Also Serve Cities Near Arcadia
Fielding ADU Builders works throughout the San Gabriel Valley. If you’re in Monrovia, Temple City, Sierra Madre, or San Gabriel, we scope projects to each city’s own plan check, the same way we do for Arcadia. You can see our full service area on our ADU Builders page, or call us directly for a quote.
Serving Arcadia, CA - Our Local Coverage Area
We’re based in the Arcadia 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 About ADU Builders in Arcadia
Most Arcadia ADU permits run 4 to 7 months from submittal to issuance, depending on whether the plans come back with comments and how quickly revisions are resubmitted. Arcadia runs its own Planning and Building counter, so the timeline is driven by city staffing and plan-check load, not a county program. Call (361) 315-4177 and we’ll review your plan set before submittal to cut down on revision cycles.
Yes, Arcadia allows both a detached ADU and a JADU on one lot when the lot size and setbacks support it, and running both through a single permit package can share one plan-check cycle. We did exactly this for a family near Camino Real Avenue, using a Plant Prefab shell for the detached unit and converting part of the existing garage into a JADU under the same review.
Most bid changes in Arcadia trace back to site conditions that weren’t priced at bid time: an existing garage on a non-conforming setback, a foundation that needs more work than expected, or utility separation the plan check requires. We price those items up front. The written price you approve before work starts is the number on the final invoice, and if something unexpected is found mid-project, we put the change in writing before any work changes.
Arcadia enforces a single-story pattern for rear-yard detached units in most residential zones, and yes, it affects cost. A single-story unit needs more foundation and roof area per square foot than a stacked two-story design, so the price per square foot runs higher. We scope single-story from the first conversation and plan the lot’s rear-yard envelope around that rule.
From first call to finished ADU in Arcadia, plan on 9 to 14 months. That includes design and plan check, 4 to 7 months of permitting, and 4 to 6 months of construction. Prefab shells can tighten framing time, but foundation work, utility trenching, and city inspections still set the critical path. Call (361) 315-4177 for a written estimate and a realistic calendar for your specific lot.
Written by Reed Calloway, Owner at Fielding ADU Builders, serving Arcadia with The Garrison Standard since 2006.



