Timeline / Detached ADUs
How a detached ADU is sequenced
A detached ADU adds utility and site steps that a remodel does not have. This page shows the dependency chain from feasibility to final inspection and where schedules usually stretch.
What moves the schedule
Feasibility before design
Lot, overlays, access and utility routes are checked first; they decide which design is worth drawing.
Utilities run on their own clock
Utility providers may review service changes separately from the building authority, and their steps can sit on the critical path.
Foundation inspections open the build
Framing does not start until the foundation is inspected, so site and soil surprises affect everything after.
02Dependency map
Illustrative sequence — order and dependencies only, no dates or durations.
Scroll the table sideways on small screens.
| Step | Waits for | Can run alongside | Decisions, lead times and readiness |
|---|---|---|---|
| Predesign1. Feasibility: zoning, overlays and access | Starts the project | — |
|
| Site investigations2. Survey, utility locations and soils | 1. Feasibility: zoning, overlays and access | — | |
| Consultant work3. Structural, civil and energy input | 2. Survey, utility locations and soils | — | California Energy Commission — 2025 Building Energy Efficiency Standards ↗ |
| Design development4. Plan choice and construction documents | 3. Structural, civil and energy input | — |
|
| Application acceptance5. Completeness check | 4. Plan choice and construction documents | — |
California Legislature — Government Code § 66317 (ADU application review) ↗ |
| Correction rounds6. Review, corrections and other departments | 5. Completeness check | 7. Sewer route, water meter and electrical service requests; 8. Window, door and equipment orders |
California Legislature — Government Code § 66317 (ADU application review) ↗ |
| Utility readiness7. Sewer route, water meter and electrical service requests | 4. Plan choice and construction documents | 6. Review, corrections and other departments; 8. Window, door and equipment orders |
Los Angeles Department of Water and Power — Request a meter spot (single-family) ↗ |
| Procurement8. Window, door and equipment orders | 4. Plan choice and construction documents | 6. Review, corrections and other departments; 7. Sewer route, water meter and electrical service requests |
|
| Permit issuance9. Permit issued | 6. Review, corrections and other departments | — | |
| Mobilization10. Access, staging and protecting the main house | 9. Permit issued | — |
|
| Construction11. Site work and foundation | 10. Access, staging and protecting the main house | — | |
| Inspections12. Foundation inspection | 11. Site work and foundation | — | |
| Construction13. Framing, systems and finishes | 12. Foundation inspection; 8. Window, door and equipment orders | — | |
| Inspections14. Rough and final inspections | 13. Framing, systems and finishes; 7. Sewer route, water meter and electrical service requests | — | |
| Closeout15. Connections, documents and handover | 14. Rough and final inspections | — |
Your progress notes
Tick a step when you consider it done. A tick is your own note, not evidence that an authority approved anything. Nothing is saved or sent.
Can start now, by your notes: 1. Feasibility: zoning, overlays and access
Distinctions that matter
Construction duration vs end-to-end
Construction time counts days trades are on site. End-to-end time adds design, engineering, review, corrections, procurement and close-out. Ask which one any schedule describes.
Agency metric vs your project
When an authority publishes review statistics, they describe past applications in aggregate. They are not a prediction for one parcel's drawings and corrections.
Why this page gives no durations
We found no published basis that would make a single number honest for every house, so the sequence and its dependencies are shown instead. Your schedule is set once drawings and review requirements are known.
Illustrative example — not a client
On one lot the sewer line can extend from the main house; on another a new connection is needed. Both buildings take the same construction effort, but the second schedule waits on the provider's steps before final.
What each phase means: phase glossary
Questions
- Does choosing a pre-approved plan settle my ADU schedule?
- No. It may reduce design and some review work where the authority offers that path, but the site plan, foundation, access and utility connections still need project-specific answers. Track each unresolved dependency and who must answer it before scheduling the next stage. A permit-review window is not the time from your first design conversation to move-in.
- Is there a state review deadline?
- For ADU applications, Government Code § 66317 sets a 15-business-day completeness notice and a 60-day decision window on a complete application (see the dependency map). These cover review steps only; correction rounds, other agencies, utilities and construction sit outside them.
Service, permits and timing
This service by community
- ADU construction in Los Angeles
- ADU construction in Beverly Hills
- ADU construction in Santa Monica
- ADU construction in West Hollywood
- ADU construction in Culver City
- ADU construction in Venice
- ADU construction in Calabasas
- ADU construction in Burbank
- ADU construction in Glendale
- ADU construction in Pasadena
- ADU construction in Malibu
- ADU construction in Inglewood
KB Remodeling · Greater Los Angeles
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