Most Redondo Beach ADU owners ask us the same question on the first walk. How long from signing drawings to a final inspection card on the wall? The honest answer is 16 to 28 weeks of construction, plus another 4 to 8 weeks of plan check at 415 Diamond Street before we ever break ground. That is a real 6 to 9 month window, and it swings on things that have nothing to do with the ADU itself — sewer lateral condition, Edison panel size, and whether your primary house has sprinklers.
We are writing this in late summer with one eye on the calendar. If you want deck and outdoor kitchen finishes tied to your new ADU done before fall rain and June Gloom fog drip, the drawings need to be at the counter now. Here is how we sequence a Redondo Beach ADU, week by week.
Weeks 1 to 4: Drawings and site checks
The first month is not glamorous. We measure, pull a topo if the lot slopes, and check three things that decide the whole job. Sewer lateral size and condition. Edison panel capacity. Setbacks from the existing structure.
State ADU law under Gov Code 65852.2 gives you a 4-foot setback from the primary house regardless of what local zoning says. That matters on Redondo Beach's typical 5,800 sqft lots, where the primary often already sits close to the side yard. We stake the ADU footprint before we finalize the floor plan, not after.
Panel capacity is the other early call. New electric kitchen plus a heat pump usually means 200A service, and if you are on an old 100A Zinsco panel the upgrade needs its own Edison coordination window. That runs parallel to plan check but has to start early.
Weeks 4 to 12: Plan check at 415 Diamond
Redondo's Building and Safety counter runs 4 to 8 weeks on typical plan check. Hours are Mon through Thu 7:30am to 5:30pm with alternate Fridays, so a Friday counter visit needs a phone call first at (310) 318-0637 to confirm they are open.
Expedited review is available in Redondo, and we use it when the client has a hard move-in date. It is not free and it does not skip corrections — it just moves you to the front of the queue for each round.
Expect at least one correction cycle. The most common flags we see are Title 24 Part 6 energy compliance on the detached ADU envelope, and fire separation details when the ADU is close to the primary. Neither is hard to clear if the drawings were built right, but each round adds two to three weeks.
Weeks 12 to 16: Permits, fees, and pre-construction
Once corrections clear, the permit issues. Redondo's fee schedule shows the ADU base at $2,200 base + $1,800 school fee waived per state law, which is the state ADU exemption at work. School fees are a real number on most residential jobs and their absence here is one of the reasons ADUs pencil.
We also pull the electrical permit at this stage if a panel upgrade is in scope. That fee is separate at $200 + inspection.
Between permit issuance and the first framing inspection, we stage materials and confirm the sewer lateral plan. One of the most frequent pitfalls on South Bay ADUs is that sewer lateral capacity often the gating factor. Older Redondo homes were built with 3-inch cast iron that is now 60 years into its service life, and adding a full ADU kitchen and bath means either a lateral upgrade or a documented capacity analysis.
Weeks 16 to 22: Foundation, framing, rough-ins
This is where a Class A and B contractor earns the fee. We self-perform structural framing and finish carpentry under one license, which means one crew, one schedule, and one warranty on the structural shell.
Foundation pour to dry-in usually runs 4 to 6 weeks on a detached ADU under 800 sqft. Rough plumbing, rough electrical, and mechanical rough follow immediately, and we stack inspections rather than call them one at a time. That saves a week or more over the life of the job.
Mini-split heat pump HVAC lines get set during rough. We prefer them over ducted systems on ADUs because there is no attic penalty and the Title 24 numbers work out cleaner.
Weeks 22 to 28: Finish, MEP trims, and final
Drywall, exterior siding, and roofing happen in parallel where the crew count allows. On coastal Redondo lots we spec Hardie panel siding (coastal-rated) — the salt air near King Harbor eats standard fiber cement fasteners inside of five years, so stainless is not optional.
TPO roofing goes down before the interior finish trades start. Rain in Redondo averages 13.6 inches a year, most of it between December and March, so a fall completion means we want the roof watertight by early October.
Final inspections stack: building, electrical, plumbing, mechanical, and energy. If the primary house has sprinklers, the ADU needs them too — that is a state code trigger, not a Redondo one, and it is one we flag at week one so nobody is surprised at final.
You can see how this sequence plays out on the South Redondo Triplex we completed, which ran multiple permit streams in parallel on a constrained coastal lot.
Seasonal notes for late-summer starts
If you are starting drawings now and want the ADU finished with deck and outdoor kitchen tied in before fall, the schedule is tight but workable. Plan check has to hit the counter this month. Framing needs to be done before the first November rain. Exterior finishes want a dry two-week window, and May Gray + June Gloom shortens the paintable days more than most owners expect.
We build the finish schedule around those windows, not the other way around. Interior work continues through the wet months.
FAQ
How long is plan check in Redondo Beach right now? Redondo publishes 4 to 8 weeks for typical residential plan check at 415 Diamond St. Expedited review is available. Expect at least one correction round.
Do I need to upgrade my electrical panel for an ADU? Often yes. A new ADU with electric kitchen and a heat pump usually requires 200A service. We check panel capacity in week one so the Edison coordination runs parallel to plan check.
Are school fees really waived on ADUs? Yes, per state law. Redondo's fee schedule reflects the $1,800 school fee waived per state law, which follows Gov Code 65852.2.
What if my house has fire sprinklers? Then the ADU needs them too. This is a state trigger. We identify it at the drawing stage because it affects layout, water service sizing, and cost planning.
Can I sell the ADU separately from my house? Under AB 1033 (2024 — allows ADU sale as condo separately from primary), some jurisdictions allow it. Redondo Beach adoption of AB 1033 is still evolving, so call the Building and Safety counter at (310) 318-0637 before assuming.