
ADUs & Additions in Arcadia
Detached ADUs, garage conversions, room additions and second storeys, designed, permitted and built. Designed, permitted and built by our own crews.
ADUs & Additions built for Arcadia properties
Arcadia rewards a contractor who reads the HOA map before the zoning map. Five recognized associations run their own architectural review boards, and their approval comes first — a fact that quietly sets the calendar for two-story additions, new builds, and even tree removals. We build around heritage oaks, gravelly canyon-fan soils, and the deep estate lots that make ambitious pool and outdoor-kitchen programs realistic here.
Ranch-era lots in the Rancho and Oaks tracts commonly run 15,000 square feet or larger with wide setbacks, while Baldwin Stocker and Village blocks sit closer to 7,000 to 9,000 square feet.
We are a design-build team, which means the people who draw your project are the people who build it. Design, engineering, permits and construction run through one project manager and our own crews, so nothing gets lost in a handoff between a salesperson and a subcontractor. We are licensed and insured, LIC #1119054.
Permits in Arcadia: Residential permits are issued by the Building Services Division within the Development Services Department, and plans are submitted through the city's online EDGE portal. New homes, rebuilds, and two-story or second-floor additions go through the city's single-family Architectural Design Review. Five City Council–recognized homeowners associations — among them the Santa Anita Oaks Association, Rancho Santa Anita Property Owners Association, and the Highlands Homeowners Association — each maintain an Architectural Review Board with design authority over their area, and that approval is obtained before filing with the city. Oak tree regulations apply, and tree removal plans inside an association area must first be reviewed by that association's Architectural Review Board.
What We Build
- HOA Architectural Review Board packages
- Architectural Design Review for two-story work
- Oak protection and arborist coordination
- Detached ADUs, ground-up
- Garage conversions to living space
- Junior ADUs within the main house
- Room additions and bump-outs
- Second-storey additions
- Full kitchens and bathrooms in the ADU
- Separate utility metering where required
- Private entries, patios and landscaping
- Plans, engineering and city submittals
- Title 24 energy compliance
Local Conditions
What building in Arcadia actually involves
Every city in Southern California builds differently. These are the things that change the scope, the schedule or the budget on Arcadia projects.
Northern tracts sit on the Santa Anita Canyon alluvial fan, where cobble and dense gravel layers slow pool digs and can force rock hammers or oversized soil export.
Heritage coast live oaks with wide root plates occupy many rear yards, so pool shells, spas, and detached structures get laid out around arborist-set protection radii.
The Raymond Fault zone clips the southern part of town, adding a geologic investigation requirement to new habitable square footage on affected parcels.
Estate lots with circular drives and gated frontage often lack a side yard wide enough for equipment, so crane picks or temporary fence removal get planned into the schedule.
Investment
What this costs in Arcadia
Real Southern California ranges, not a teaser number. Every project is priced line by line after we have seen the site.
Detached ADU
$150,000 to $400,000+
What moves it: square footage, finish level, utility runs, and site access; garage conversions typically run well below a ground-up detached build
Garage conversion ADU
$80,000 to $180,000
What moves it: whether the existing slab and framing meet current code, how far utilities have to run, and the finish level of the kitchen and bathroom
Plans, drawings and permit management
$4,500 to $25,000+
What moves it: project type and size, whether structural engineering, Title 24 or a soils report is required, and how many jurisdictions or review bodies are involved
How We Build
Your Arcadia project, step by step
Feasibility
We check lot size, setbacks, utilities and access to confirm what your property will actually support.
Design & 3D
Layout, elevations and finishes, modelled in 3D so you approve the unit before submittal.
Plans & Permits
We prepare the full drawing set, handle engineering and Title 24, and manage the city submittal and corrections. In Arcadia that submittal goes to City of Arcadia Development Services Department, Building Services Division.
Foundation & Framing
Site prep, foundation, framing and dry-in by our own crews.
Systems & Finishes
Electrical, plumbing, HVAC, insulation, then kitchen, bath and interior finishes.
Final Inspection
We pass final inspection, walk the unit with you and hand over the keys.
Arcadia Questions
Common questions from Arcadia homeowners
Who issues the permits for this work in Arcadia?
City of Arcadia Development Services Department, Building Services Division. Residential permits are issued by the Building Services Division within the Development Services Department, and plans are submitted through the city's online EDGE portal. New homes, rebuilds, and two-story or second-floor additions go through the city's single-family Architectural Design Review. Five City Council–recognized homeowners associations — among them the Santa Anita Oaks Association, Rancho Santa Anita Property Owners Association, and the Highlands Homeowners Association — each maintain an Architectural Review Board with design authority over their area, and that approval is obtained before filing with the city. Oak tree regulations apply, and tree removal plans inside an association area must first be reviewed by that association's Architectural Review Board. We prepare the drawings, make the submittal and handle plan-check corrections ourselves, so you are not the one chasing the city.
What makes building in Arcadia different?
Ranch-era lots in the Rancho and Oaks tracts commonly run 15,000 square feet or larger with wide setbacks, while Baldwin Stocker and Village blocks sit closer to 7,000 to 9,000 square feet. In practice that means northern tracts sit on the Santa Anita Canyon alluvial fan, where cobble and dense gravel layers slow pool digs and can force rock hammers or oversized soil export..
Which parts of Arcadia do you work in?
All of it, including Santa Anita Oaks, Upper Rancho, Lower Rancho, Arcadia Highlands. We are based in Los Angeles at Cahuenga Pass, so Arcadia is a short run for our crews rather than a job we service from out of the area.
What does adus & additions cost in Arcadia?
Detached ADU in this market generally runs $150,000 to $400,000+. What moves it is square footage, finish level, utility runs, and site access; garage conversions typically run well below a ground-up detached build. We give line-item pricing after seeing the site rather than quoting a number over the phone.
How long does an ADU take start to finish?
Plan a realistic year. Design and engineering typically take one to three months, city plan check and corrections add several more, and construction usually runs four to eight months depending on size and site access.
Is a garage conversion cheaper than a detached ADU?
Usually yes, and often substantially, because the foundation, walls and roof already exist. The trade-offs are that you lose the garage, and older slabs and framing sometimes need upgrading to meet current code.
Can I rent the ADU out?
California ADU law is designed to allow long-term rental, and an ADU is one of the few ways to add rentable square footage to a single-family lot. Short-term rental rules vary by city, so confirm your local ordinance before counting on that income.
Do you handle the permits?
Yes. Plans, engineering, Title 24 and the city submittal are all handled in-house, including responding to plan-check corrections. That is a service we sell on its own, so it is not something we hand off.
More services in Arcadia
Arcadia Guides
Planning guides for Arcadia homeowners
Costs, materials and process notes from our own projects.
ADU Cost Breakdown by Size in Los Angeles
A detached ADU in Los Angeles runs $150,000 to $400,000-plus. Here is the real cost broken down by unit size, with the soft costs, utility work and finish decisions that move the number.
Read guideGarage Conversion to ADU: The Step-by-Step Build
A garage conversion runs $80,000 to $180,000 in Southern California. Here is the real sequence, from slab testing and plan check to the raised floor, the mini-split and final sign-off.
Read guideADU Rental Income Maths in the San Fernando Valley
A one-bedroom ADU in the San Fernando Valley rents for roughly $2,100 to $2,900 a month. Here is the honest arithmetic on payback, carrying costs and what the unit adds to the property.
Read guideSecond Storey Addition vs Building Out: Which Costs Less
Building out runs $350 to $500 per square foot. Going up runs $450 to $700. Here is when the cheaper option is actually the wrong one, and what drives each number.
Read guidePlanning adus & additions in Arcadia?
Sit down with your project manager, go through the details, and get an accurate estimate for your property.
Licensed & Insured · LIC #1119054
