ADU builder · Arcadia, CA
ADU builder in Arcadia.
Design, permits, financing and construction from one local team. 600+ ADUs delivered across greater LA, including nearby Monrovia, Sierra Madre & Pasadena.
Licensed & insured · Construction from $275/sq ft · 5.0★ rated
Building an ADU in Arcadia
Arcadia has a lot of large single-family lots, and that room makes a second home on the property workable, whether it's for parents, adult children or a rental. ADU permits have climbed steadily, from about 70 in 2023 to about 98 in 2025, per state housing reports. North of the flats the city runs up into the foothills, where slopes and fire zones change how an ADU is built.
ADU Resource Center designs, permits and builds ADUs with one in-house team. Our nearest work is next door: a Craftsman ADU in Monrovia, a mid-century ADU and a pair of 750 sq ft units in Sierra Madre, and an attached 2-bedroom ADU in Pasadena.
Before any work starts you get a fixed quote for your lot. One project manager handles the job from the first drawings to final inspection, and we can help you compare financing options.
ADUs in Arcadia: quick facts
Updated November 2026
- Who issues ADU permits
- City of Arcadia
- Our construction rates
- $275, $300 or $325 per sq ft (basic, mid-range, luxury); garage conversions $235–$285 per sq ft
- Example cost
- A 600 sq ft one-bedroom runs about $165K–$195K in construction
- Size limits under state law
- Detached ADUs up to 1,200 sq ft on many lots; junior ADUs up to 500 sq ft inside the home
- Permit decision
- State law requires a decision within 60 days of a complete application
- Who builds it
- ADU Resource Center: design, permits and construction by one team, 600+ ADUs delivered, office in Glendale
ADU rules change. We confirm the current rules for your lot on the free consultation.
Real projects nearby
ADUs we've built near Arcadia.
Hear it from our clients
Homeowners on building their ADU with us
More stories on our testimonials page.
Local know-how
What to know before building in Arcadia.
Arcadia runs its own permits
Plans go to the City of Arcadia's Development Services Department. We prepare the submittal and handle each round of corrections.
Deep lots and utility distance
Setting the ADU at the back of a deep Arcadia lot means longer sewer, water and electrical lines, and sometimes a bigger panel. We weigh that against privacy when we pick the spot. The cost calculator gives a quick number for the building itself.
Foothill fire zones
Neighborhoods toward the mountains include very high fire hazard severity zones. That means ignition-resistant roofing, vents and siding, and sometimes a soils report on sloped lots.
Space for a full-size unit
Larger Arcadia lots can often fit a 2- or 3-bedroom ADU. Look through our 39 floor plans to get a feel for sizes, and we'll confirm what your lot allows.
What it costs
ADU cost in Arcadia
We build at a flat rate per square foot: $275 (basic), $300 (mid-range) and $325 (luxury) finishes. Here's what that means for common sizes. Construction only; design, permits and city fees are quoted separately on your consultation.
| ADU size | Basic | Mid-range | Luxury |
|---|---|---|---|
| 400 sq ft studio | ~$110K | ~$120K | ~$130K |
| 600 sq ft 1-bedroom | ~$165K | ~$180K | ~$195K |
| 800 sq ft 2-bedroom | ~$220K | ~$240K | ~$260K |
| 1,000 sq ft 2–3 bedroom | ~$275K | ~$300K | ~$325K |
Get a number for your exact size: ADU cost calculator · Browse ADU floor plans · Converting a garage? See garage conversion cost.
Free consultation
Start your Arcadia ADU.
Tell us about your property. We'll confirm what's buildable, give you a real price range and walk through financing within 1 business day.
Questions
Arcadia ADU questions, answered.
Still have a question? Ask us during your free consultation.
Who issues ADU permits in Arcadia?
Arcadia is its own city, so ADU plans go to the City of Arcadia's Development Services Department rather than LA City or LA County. We draw the plans, submit them, respond to plan-check corrections and pull the permits for you.
How much does an ADU cost in Arcadia?
We build at a flat $275, $300 or $325 per sq ft for basic, mid-range or luxury finishes. A 600 sq ft one-bedroom comes to about $165K–$195K in construction, and a garage conversion runs $235–$285 per sq ft. Long utility runs to the back of a deep lot, or a slope in the foothills, can change the fixed quote.
Can I build an ADU on a large Arcadia lot?
Most single-family lots can take a detached ADU, an attached ADU or a garage conversion, plus a junior ADU of up to 500 sq ft inside the house. State law allows detached ADUs up to 1,200 sq ft on many lots, and bigger Arcadia lots often have room for that. Placement still depends on setbacks and utilities, which we check on the consultation.
Are parts of Arcadia in a fire hazard zone?
Yes. The northern foothill neighborhoods include very high fire hazard severity zones, and CAL FIRE released updated maps in 2025. A parcel in that zone needs ignition-resistant construction, so we look up your address on the current map before design.
Have you built ADUs near Arcadia?
Our closest projects are next door in Sierra Madre and Monrovia, plus several in Pasadena. They include a 1,000 sq ft mid-century ADU for parents and two 750 sq ft ADUs on one former duplex lot.
Free consultation
Ready to build your ADU in Arcadia?
Tell us about your property and we'll confirm what's buildable, give you a real price range and lay out financing on one free call.
