Published: 7 Oct 2026 · Last verified: 7 Oct 2026 · Next review: Jan 2027 Cost figures are re-checked against permit records quarterly. Changes are logged in Corrections.
Anaheim charges the steepest development impact fees in this series — and runs the most polished pre-approved ADU program. That tension is the whole story.
The city’s 2026 impact-fee overhaul — its first since 2011 — sets residential rates that total $19,521 per unit, driven by a $16,022 parks fee. An 800 sq ft ADU, clearing the 750 sq ft cliff, pays a proportional share: our example math lands at ~$10,411 on a 1,500 sq ft house, the largest ADU impact-fee line we have published. Against that, the building permit is a relative bargain at $1,672 with plan check included — the only combined permit fee in the series — and ADU Express hands out four free pre-approved plans with a seven-step process. Our six-phase total lands at $320,000, or $400 per square foot — exactly the LA County baseline, built from very different parts.
Four assumptions sit underneath that total, each marked where it appears: the permit-fee category applied to ADUs, the final adoption and calculation basis of the 2026 impact-fee update, whether the regional sewer charge applies, and city water connection charges. We emailed the city’s Building Division on Oct 7, 2026 with these questions and the city replied the same day, after publication — confirming the sanitation average of $1.71 per square foot, that park fees apply to construction of 750 square feet and above, and referring school-fee (address-specific) and water-connection questions to the relevant departments. Construction phases 2–6 are carried from the Los Angeles County baseline; Anaheim does not publish phase-level construction costs.
The short answer
| 800 sq ft detached ADU · Anaheim · 2026 | Amount |
|---|---|
| Total build cost (see assumptions) | $320,000 |
| Cost per square foot | $400 |
| Largest single line | Systems + interior, $147,000 |
| School district fees (two districts) | $4,304 |
| OC San sewer capacity charge | $1,368–$1,710 (city confirmed $1.71/sq ft avg; rounding basis unconfirmed) |
| Building permit, plan check included (assumed category) | ~$1,672 (assumed) |
| DIF — four fees, pro-rata (assumed interpretation) | ~$10,411 (assumed) |
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) | $32,000 | 10% |
| 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 | $320,000 | $400 / 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 (ADU Express offers 4 free plans as an alternative) |
| Building permit (plan check included) | ~$1,672 | “Combined Plan Check and Building Permit Fees,” Tier 3 — assumes Residential Category 2; the city’s ADU classification is unconfirmed |
| School fees (AESD + AUHSD) | $4,304 | $5.38/sq ft × 800 — AUHSD $2.69 verified in May 2026 resolution; AESD $2.69 via 50/50 split collected by AUHSD |
| DIF — police/fire/library/parks, pro-rata (example) | ~$10,411 | $19,521 × 800/1,500 — the 2026 resolutions’ final adoption and the calculation basis are unconfirmed |
| OC San capacity charge (CFCC) | $1,368–$1,710 | The city confirmed the $1.71/sq ft average in its Oct 7, 2026 reply — $1,368 at 800 sq ft on a straight average vs. $1,710 if OC San Table A’s “per 1,000 sq ft or portion thereof” rounds up; the rounding basis and applicability to a detached ADU are unconfirmed |
| City water / sewer connection | $0 | Existing connections used; an ADU “contained within the existing space” is not a new dwelling unit — new detached ADU connection charges are unconfirmed |
The highest impact fees in the series
Anaheim’s 2026 development impact fee update is the first since 2011, and it moved a lot. The DTA justification study and the March 2026 council agenda set residential rates at $1,128 (police), $759 (fire), $1,610 (library), and $16,022 (parks) per unit — $19,521 combined. The parks fee alone is larger than Fullerton’s entire park dwelling fee line, and the city’s own study justifies a parks maximum of $45,777 per unit (the council adopted roughly 35% of it).
For an 800 sq ft ADU the math is proportional, not flat: the fee equals the unit rate times the ADU’s square footage divided by the primary dwelling’s. The study’s own worked example — an 800 sq ft ADU on a 2,500 sq ft house — comes to $15,847, but that example uses the maximum justified rate ($49,523), not the adopted rate. On adopted rates with a 1,500 sq ft primary dwelling, the ADU’s share is ~$10,411. Which basis the city actually applies is one of our unconfirmed items, and the answer swings the number between roughly $6,247 and $26,412. In its Oct 7, 2026 reply to our inquiry, the city confirmed that park fees are assessed on construction of 750 square feet and above.
One citation note: the city’s DIF materials quote Government Code §66324 for the definition of “impact fee” — technically accurate, and the same pattern Fullerton’s ordinance uses. The ADU exemption rules themselves live in §66311.5, which the city’s pro-rata structure follows.
The only combined permit in the series
Every other city in this series bills plan check separately — usually as a percentage of the permit fee (Garden Grove 65%, Fullerton 87% plus 20% energy). Anaheim’s fee schedule is titled “Combined Plan Check and Building Permit Fees”: the $1,672 covers both. At 800 sq ft under the assumed Residential Category 2 tier ($1,225 for the first 500 sq ft plus $148.93 per additional 100 sq ft), that is the complete permit-plus-review cost — no 87% or 65% add-on. Whether the city actually classifies a detached ADU under Category 2 is unconfirmed, but the combined structure itself is verified in the published schedule.
ADU Express: the series’ most developed pre-approved program
Anaheim’s ADU Express is a genuine seven-step pipeline, not a PDF of floor plans. An online eligibility tool checks the address, the applicant picks from four free detached designs (studio at 224 sq ft, one-bedroom at 499, two-bedroom at 990, three-bedroom at 1,199), Anaheim Public Utilities does a free “meter spot” visit — typically within three business days — and the applicant emails the meter report plus the plan number to ADUExpress@anaheim.net before a city-hall meeting to draw up the site plan.
The fee logic of the four plans is worth noting: the 224 and 499 sq ft designs sit under the 750 sq ft impact-fee cliff and pay $0 in DIF. The 990 and 1,199 sq ft designs clear it and pay proportionally. The 1,199 sq ft plan matches the ordinance maximum for lots of 19,000 sq ft or more — the biggest pre-approved design in the series.
The 750 cliff
State law draws the line every city in this series follows: no impact fees under 750 sq ft, proportional fees at 750 and above (Gov. Code §66311.5). In Anaheim the cliff matters more than anywhere else because the underlying rates are the highest: a 749 sq ft design pays $0 in DIF while an 800 sq ft design on a 1,500 sq ft house pays ~$10,411 in our example. The school-fee cliff sits lower — 500 sq ft under SB 543 — so an 800 sq ft ADU pays school fees on the full area regardless.
Anaheim vs. Los Angeles County
| Anaheim | LA County baseline | |
|---|---|---|
| Total | $320,000 | $320,000 |
| Per sq ft | $400 | $400 |
| Building permit (+ plan check) | ~$1,672 combined | carried |
| DIF (pro-rata example) | ~$10,411 | carried |
| School fees | $4,304 | $4,304 |
| Pre-approved plans | 4, free, in production | none |
| ADU permits 2022–2024 (HCD) | top 12 statewide | — |
The $0 gap is a coincidence of the example math, not a finding — the four unconfirmed assumptions dominate it. The real story is the composition: the series’ highest impact fees paired with its only combined permit fee and its most developed free-plan program.
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. Anaheim’s current ADU-to-primary-dwelling pro-rata structure will need a rewrite. We found no mention of SB 1117 in city materials; the January 2027 quarterly review will check for an updated ordinance.
Disclaimer
Model estimate, not a quote. Fees change; the assumptions above are the city’s to confirm — we emailed the City of Anaheim Building Division on Oct 7, 2026 about the five unconfirmed items and received a reply the same day, after publication: sanitation averages $1.71/sq ft, park fees apply to construction of 750 sq ft and above, and school-fee and water-connection questions were referred to the relevant departments. The 2026 impact-fee adoption and calculation basis remain unconfirmed. Always verify current fees with the City of Anaheim Planning & Building Department before budgeting.