Published: 8 Oct 2026 · Last verified: 8 Oct 2026 · Next review: Jan 2027 Cost figures are re-checked against permit records quarterly. Changes are logged in Corrections.
Torrance charges its ADU impact fee the way a parking meter charges: one flat number, no math. $2,243.47 per ADU — not a ratio of the ADU to the house, not a percentage of valuation, just the number. Burbank makes you divide the ADU by the primary dwelling and add a 5% surcharge; Fullerton’s pro-rata lands near $6,411 on a 1,500 sq ft house. Torrance skips all of it. It is the first flat-rate ADU impact fee in this series, and at roughly one-third of Fullerton’s, the lowest DIF we have published.
The number comes with a bureaucratic quirk worth reading twice. Torrance’s ADU ordinance — Ordinance No. 3954, adopted unanimously August 5, 2025 — contains no 750 sq ft cliff language at all. The cliff exists as a single line in the Planning Fee Schedule: “Accessory Dwelling Unit: $2,243.47/unit — ADU 750 SF or greater in size.” In every other city we have published, the cliff lives in the ordinance. Here, the fee schedule defines it. Our six-phase total lands at $317,000, or $396 per square foot — just under the LA County baseline, built from very different parts.
Seven assumptions sit underneath that total, each marked where it appears: the construction valuation rate, whether three city taxes apply to ADUs, whether plan-check add-ons apply to residential ADUs, the existence of a pre-approved ADU plan program, and the current fiscal year’s fee schedule. We emailed the city’s Community Development Department on 7 Oct 2026 with all seven questions; this post will be updated when they reply. Construction phases 2–6 are carried from the Los Angeles County baseline; Torrance does not publish phase-level construction costs.
The short answer
| 800 sq ft detached ADU · Torrance · 2026 | Amount |
|---|---|
| Total build cost (see assumptions) | $317,000 |
| Cost per square foot | $396 |
| Largest single line | Systems + interior, $147,000 |
| Building permit + plan check | ~$3,608 (valuation assumed) |
| DIF — flat ADU rate | $2,243 (series lowest) |
| School district fee (single district) | $4,304 |
| Water / sewer new connection | $0 (existing connection shared) |
| Unconfirmed city taxes (3 lines) | ~$4,951 (assumed applicable) |
The full line-item breakdown
Six phases. The same six used on every build in this series.
| Phase | Cost | Share |
|---|---|---|
| Soft costs (design, permits, fees) | $29,000 | 9% |
| Site work + foundation | $38,000 | 12% |
| Framing + structure | $48,000 | 15% |
| Building envelope | $42,000 | 13% |
| Systems + interior | $147,000 | 46% |
| Landscaping & hardscape | $13,000 | 4% |
| Total | $317,000 | $396 / sq ft |
The fee autopsy
Every fee line we found, with exactly what it is and where it came from.
| Fee line | Amount | Source / status |
|---|---|---|
| Design & engineering | $14,000 | Series baseline, carried — no pre-approved ADU plan program found in city materials (absence not officially confirmed) |
| Building permit | ~$2,122 | Valuation $161,120 assumed (800 × $201.40 — FY 2026/27 rate table PDF text extraction failed, matches ICC BVD Aug 2024 R-3 Type VB but unverified). Tier $100,001–$250,000: $1,471.39 + 61.12 × $10.65 — FY 2024/25 Master Fee Schedule |
| Plan check — Plan Review | ~$1,486 | 70% of building permit — same schedule |
| Community Planning Fee | ~$209 | 0.13% of valuation — same schedule |
| Plan check add-ons (Handicap / Energy / Green / NPDES) | not counted | Rates listed (60% / 60% / 60% / 20% of permit) — whether they apply to a residential ADU is unconfirmed |
| DIF — ADU flat rate | $2,243.47 | “Accessory Dwelling Unit: $2,243.47/unit — ADU 750 SF or greater in size.” — Planning Fee Schedule FY 2024/25 & Beyond |
| School fee (Torrance USD) | $4,304 | $5.38/sq ft × 800 — Resolution #AS-11-25/26 (adopted 2026-06-15, effective 2026-08-14). City Building & Safety page still shows the old $5.17 rate — stale |
| Park & Recreation Facilities Tax | $550 | $550/dwelling unit — ADU applicability unconfirmed |
| Dwelling Unit Tax | $1,984 | $1,984/dwelling unit — ADU applicability unconfirmed |
| Construction Tax | ~$2,417 | 1.5% of valuation — ADU applicability unconfirmed |
| Water — new service connection | $0 | Existing connection shared — Gov. Code §66311.5 (schedule lists 3/4”–1” new connections at $4,535) |
| Sewer — building sewer (plumbing permit) | $73.50/unit | Master Fee Schedule, plumbing section — nominal |
| Sewer capacity charge | none found | No ADU sewer capacity charge line item exists in the schedule |
The flat-rate DIF: a series first
Every city in this series charges ADU impact fees, and every one before Torrance scales them to something — the house, the valuation, the unit count. Burbank’s formula ($15,166.33 × ADU square footage ÷ house square footage + 5% surcharge) is the most elaborate; Fullerton’s pro-rata lands near $6,411 on a 1,500 sq ft house. Torrance’s Planning Fee Schedule has one line: “Accessory Dwelling Unit: $2,243.47/unit — ADU 750 SF or greater in size.”
The practical effect: a homeowner building an 800 sq ft ADU behind a 1,200 sq ft cottage pays exactly what a homeowner behind a 3,000 sq ft house pays — $2,243.47. There is no lever to pull, no assessor lookup, no surcharge. At roughly one-third of Fullerton’s pro-rata, it is the lowest DIF in the series by a wide margin, and the simplest to budget.
The 750 sq ft cliff is state law (Gov. Code §66311.5): under 750, $0. The schedule’s “750 SF or greater” phrasing matches it. What the schedule does not do is say anything about ADUs under 750 anywhere else — which brings us to the quirk.
The cliff that lives in the fee schedule
Ordinance No. 3954 rewrote Torrance’s ADU rules in August 2025 — consolidating the ADU and JADU sections into a single TMC 92.2.10, adding objective design standards, banning short-term rentals under 30 days, and writing the state’s own supremacy into the purpose clause: “In any instance where there is conflict, State law shall govern.” It is the only ordinance in this series that demotes itself that plainly.
It also never mentions the 750 sq ft cliff. The impact-fee threshold exists only in the Planning Fee Schedule’s one line. The ordinance does not restate it, qualify it, or exempt anything from it. For a homeowner, the consequence is minor — the schedule is what the counter charges. For the series, it is a structural first: everywhere else, the ordinance defines the cliff and the schedule prices it. In Torrance, the schedule does both jobs.
$5.38: the top tier, with a stale city page
Torrance Unified School District’s Resolution #AS-11-25/26 set the residential developer fee at $5.38 per square foot — the state maximum — adopted June 15, 2026, effective August 14, 2026. On 800 sq ft, that is $4,304, tying Glendale and Long Beach for the highest school-fee tier in the series. Torrance is a single-district city, so there is no split to track, and there is no Level 2 history — Level 1 only. The 500 sq ft cliff (SB 543) means the full area is levied either way.
One caution, and it is the city’s own: the Building & Safety page that lists ADU costs still shows the old $5.17 rate. The resolution is the controlling document. We use $5.38.
No sewer capacity charge, no pre-approved plans
Burbank put a 750 sq ft cliff on its sewer facilities charge ($908 for our example). Anaheim routes ADUs through OC San ($1,368–$1,710). Torrance has no ADU sewer capacity charge at all — the schedule contains no such line item, and the only sewer-adjacent fee is the $73.50 plumbing-permit building sewer connection. Water is the same story: new 3/4”–1” connections are priced at $4,535 in the schedule, but state law (§66311.5) bars the city from requiring a new or separate connection for an ADU on an existing single-family lot, so the example pays $0 by sharing the existing service.
On design, Torrance is the bare counter. Garden Grove hands out four free ADU plans (ADU Go); Anaheim hands out four free with a seven-step pipeline (ADU Express); Glendale runs its own program. Torrance’s website shows no pre-approved or free ADU plan program — we searched and found nothing, though no official document confirms the absence. Our $14,000 design line stays at the series baseline. We have asked the city; if a program exists, the post will be corrected.
Torrance vs. Los Angeles County
| Torrance | LA County baseline | |
|---|---|---|
| Total | $317,000 | $320,000 |
| Per sq ft | $396 | $400 |
| Building permit + plan check | ~$3,608 (valuation assumed) | carried |
| DIF | $2,243 flat (series lowest) | carried |
| School fee | $4,304 (top tier, single district) | $4,304 |
| Sewer capacity charge | none found | carried |
| Water connection | $0 (shared) | carried |
| Pre-approved ADU plans | none found | none |
| ADU permits 2022–2024 (HCD) | 776, 15th statewide | — |
The $3,000 gap is dominated by the assumed taxes. If the three unconfirmed city taxes ($550 + $1,984 + ~$2,417) do not apply to ADUs, the total falls to about $312,000 — the honest floor. The real story is the composition: the series’ only flat-rate DIF, its only schedule-defined cliff, top-tier school fees, and no sewer capacity charge, all netting to just under the baseline.
A note on SB 1117
Signed September 2026, effective January 2027: for a homeowner’s first two ADUs, impact fees may apply only to square footage above 750, calculated marginally. Torrance’s flat-rate structure — “750 or greater, $2,243.47” — cannot survive that math unchanged: an 800 sq ft ADU would owe fees on 50 sq ft, not 800, which requires a per-square-foot rate the current schedule does not publish. We found no mention of SB 1117 in city materials; the January 2027 quarterly review will check for a revised fee schedule. School fees are outside SB 1117’s impact-fee definition and stay at $4,304. Whether the three city taxes fall inside it is a question of interpretation — it is on our list to the city.
Disclaimer
Model estimate, not a quote. Fees change; the assumptions above are the city’s to confirm — the construction valuation rate, the three city taxes’ applicability to ADUs, the plan-check add-ons, the pre-approved plan program’s existence, and the current fee schedule are all marked where they appear. Always verify current fees with the City of Torrance Community Development Department before budgeting.