ADU builder · Monrovia, CA
ADU builder in Monrovia.
Design, permits, financing and construction from one local team. 600+ ADUs delivered across greater LA, including projects in and around Monrovia.
Licensed & insured · Construction from $275/sq ft · 5.0★ rated
Building an ADU in Monrovia
Monrovia has many older homes, Craftsman houses among them, on streets that climb toward the foothills, and lots with a detached garage or open space in back. If your house has character, the ADU can be designed to match it. The city has issued a steady stream of ADU permits, about 42 in 2023 and about 58 in each of 2024 and 2025, per state housing reports.
ADU Resource Center designs, permits and builds ADUs in Monrovia with one in-house team. Here we built a detached Craftsman ADU with sage green lap siding, a covered porch with a stained wood ceiling, and green shaker cabinets in an open kitchen that slides out to a paver yard. Next door in Sierra Madre we've built two more, and we also cover Arcadia.
Your fixed quote comes before construction, so any Craftsman details you choose are priced up front. A single project manager runs the job through final inspection, and we help with financing if you need it.
ADUs in Monrovia: quick facts
Updated November 2026
- Who issues ADU permits
- City of Monrovia
- 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 in and around Monrovia
Our work in and around Monrovia.
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 Monrovia.
Two reviews at the city
Monrovia's Community Development Department reviews ADUs in two steps, Planning and then Building. The city also offers a conceptual review if you want early feedback, and we can use it on tricky lots.
Foothill fire zones
Lots toward the mountains include very high fire hazard severity zones, and the 2025 CAL FIRE maps reclassified some of them. Ignition-resistant roofing, vents and siding are part of the design when your parcel is in one.
Matching an older house
Lap siding, trim profiles and a porch like the main house cost a little more than a plain stucco box. Our cost calculator gives a starting number by finish level.
Detached garages
Plenty of Monrovia lots have an old detached garage. Converting it reuses the structure, though older garages can need foundation or framing work. See garage conversion costs.
What it costs
ADU cost in Monrovia
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 Monrovia 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
Monrovia ADU questions, answered.
Still have a question? Ask us during your free consultation.
Who issues ADU permits in Monrovia?
Monrovia is its own city. ADU applications go to the Community Development Department, where Planning reviews the zoning side and the Building Division handles plan check. We prepare both submittals, answer corrections and pull the permits.
Can a new ADU match my Craftsman house?
Yes. Our Monrovia ADU has lap siding, white window trim and a covered front porch with square columns, so it reads like part of the property. We can match siding, trim and roof pitch to your house in the design.
How much does an ADU cost in Monrovia?
Construction runs 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 roughly $165K–$195K, and garage conversions run $235–$285 per sq ft. Custom exterior details or a sloped foothill lot can raise the fixed quote, and we spell that out before you sign.
Does a fire hazard zone affect an ADU in Monrovia?
It can. Monrovia's foothill neighborhoods include very high fire hazard severity zones, and CAL FIRE's 2025 maps changed the rating on some parcels. In those zones the ADU needs ignition-resistant materials, and the city may require extra review, so we check your parcel first.
Can I add a junior ADU too?
On many single-family lots, yes. A junior ADU of up to 500 sq ft can go inside the house in addition to a detached ADU, which gives some families three homes on one lot. We confirm what your lot allows under current Monrovia and state rules, since ADU rules change.
Free consultation
Ready to build your ADU in Monrovia?
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.
