Service 03 • Ground-Up Construction
Detached ADU Construction in Orange County.
Build a private, standalone dwelling in your backyard. From compact 350 sq ft studios to spacious 1,200 sq ft 2-bedroom luxury residences, our licensed craftsmen handle excavation, foundation, framing, plumbing, electrical, and turnkey luxury finishes.
Typical Timeline
3 to 5 Months Build Time
City Permits
100% In-House
Contractor License
Class B Alliance
2026 COST BREAKDOWN • LINE-ITEM TRANSPARENCY
Estimated Line-Item Costs for Detached ADU Construction
Real budget allocations across architectural drawings, city permit fees, utility trenching, and turnkey construction in Orange County.
| Cost Component | Typical Range | Key Details & Code Notes |
|---|---|---|
| Architectural Plans & Structural Engineering | $6,000 - $9,500 | Includes Title 24 energy calculations & 3D renderings |
| Municipal Plan Check & City Permit Fees | $2,500 - $5,000 | Exempt from school impact fees if under 500 sq ft |
| Plumbing Trenching & Sewer Utility Connection | $8,000 - $18,000 | Independent subpanel & dedicated water tie-in |
| Structural Foundation & Framing Scope | $35,000 - $85,000 | Engineered slab pour or garage envelope retrofit |
| Interior Finishes, Kitchen & Bath Turnkey | $28,000 - $55,000 | Quartz counters, mini-split HVAC & custom cabinetry |
SCOPE SPECIFICATIONS
What's Included in Your Single-Contract Scope
Engineered slab or raised foundation & structural framingFull architectural compliance and licensed Class B construction oversight.
Independent utility connections & separate subpanelFull architectural compliance and licensed Class B construction oversight.
Designer kitchens, quartz countertops & walk-in showersFull architectural compliance and licensed Class B construction oversight.
Dedicated superintendent on-site through final inspectionFull architectural compliance and licensed Class B construction oversight.
Request Your Detached ADU Construction Quote
Get exact line-item estimates and municipal permit review details for your property within 1 business day.
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