Published: 6 Oct 2026 · Last verified: 6 Oct 2026 · Next review: Jan 2027 Cost figures are re-checked against permit records quarterly. Changes are logged in Corrections.
Glendale wrote the most interesting ADU ordinance in this series — and then made the math almost impossible to do by hand.
The ordinance does two things at once. First, it caps detached new-construction ADUs at 800 square feet — the exact size this series models. Second, it exempts ADUs under 750 square feet from all development impact fees. Put those together and you get the series’ tightest squeeze: the largest ADU Glendale allows (800 sq ft) sits exactly 50 square feet above the fee cliff. Build at 749 and the impact-fee line is $0. Build at the 800 maximum and it can reach $4,700. There is no size in between that avoids the question.
So this post does two things. First, the standard six-phase breakdown for an 800 sq ft detached ADU in Glendale — $318,000, or $398 per square foot. Then the part nobody publishes: an autopsy of the soft-cost line, fee by fee, from the city’s own schedule and ordinance — including the one line (the building permit) that the city prices by valuation but never tells you the valuation.
The short answer
| 800 sq ft detached ADU · Glendale · 2026 | Amount |
|---|---|
| Total build cost | $318,000 |
| Cost per square foot | $398 |
| Largest single line | Systems + interior, $147,000 |
| Building permit + plan check (worked example) | ≈ $8,550 |
| DIF — Parks and Library (800 sq ft) | $0 – $4,700 (main-house proportional) |
| School district fees (GUSD) | $4,304 |
| Water / sewer capacity charges | $0 (existing service shared) |
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) | $30,000 | 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 | $318,000 | $398 / sq ft |
Shares rounded.
The honest caveat, same as every city post: Glendale’s agencies do not publish phase-level construction costs, and we found no public Glendale permit-valuation dataset to anchor one. So phases two through six are carried from the Los Angeles County baseline, unchanged — we will not print a number we cannot anchor. What is rebuilt from Glendale sources, line by line, is the soft-cost phase — with one transparent exception. The city publishes its permit rate tiers but not the residential valuation table ($/sq ft) that feeds them, so the building-permit line below is a worked example at a stated valuation, not a rate-table lookup. Everything else is arithmetic from published numbers.
Where Glendale differs from Los Angeles
| Phase | LA County | Glendale | Difference |
|---|---|---|---|
| Soft costs | $32,000 | $30,000 | −$2,000 |
| Site work + foundation | $38,000 | $38,000 | — |
| Framing + structure | $48,000 | $48,000 | — |
| Building envelope | $42,000 | $42,000 | — |
| Systems + interior | $147,000 | $147,000 | — |
| Landscaping & hardscape | $13,000 | $13,000 | — |
| Total | $320,000 | $318,000 | −$2,000 |
| Per sq ft | $400 | $398 | −$2 |
The $2,000 gap is the net of offsetting forces. Working in Glendale’s favor: no water or sewer capacity charges by written ordinance, and a permit-review structure with no ADU surcharges. Working against it: the highest school-district fee in the series (tied with Long Beach) and a plan-check stack that runs 140% of the building permit across four departments — the steepest review multiplier we have seen.
The fee autopsy: $30,000, line by line
Building permit: ≈ $2,757 (worked example — read the caveat). The FY 2026-27 fee schedule (effective 8/22/2026) prices the $100,001–$500,000 valuation tier at $1,756 plus $4.55 per additional $1,000. What the schedule does not publish is the residential construction valuation table — the $/sq ft figure the building department actually multiplies by 800. We work the example at the $320,000 build valuation: $1,756 + 220 × $4.55 = $2,756.60. That is conservative — declared valuations typically run below contract price — and the real number moves with whatever valuation the plan checker assigns. If your valuation lands in a different tier, redo this line; the formula is public even when the input is not.
Plan check: 140% of the permit, plus a 50% surcharge. Four departments each take a percentage of the building permit fee (FY 2026-27 schedule): Building 115%, Planning 5%, Public Works 15%, GWP 5% — 140% combined, or about $3,860 on our worked permit. Then the Permit Program Surcharge adds 50% of plan check (another ≈ $1,930). All-in, the permit counter approaches $8,550 before a single impact fee — the heaviest review load in the series, driven by multiplier stacking rather than high base rates.
Development impact fees: $0 – $4,700 (the 50 sq ft cliff). The ADU ordinance (Section D.16) is explicit: ADUs under 750 sq ft are exempt from any development impact fee; ADUs of 750 sq ft or greater pay a Parks and Library fee proportional to the main dwelling’s square footage, capped at the fee-resolution amount — $4,700 per the FY 2026-27 schedule’s ADU row. An 800 sq ft ADU always triggers it; the exact amount depends on your main house. We carry the midpoint ($2,350) in the soft-cost total and the full range everywhere else. One open question: whether the separate Quimby fee ($19,795 single-family) also applies to 750+ sq ft ADUs — the ordinance names only the Parks and Library fee, and we could not confirm Quimby’s treatment from public documents.
School fees: $4,304 — tied for the series high. Glendale Unified School District charges $5.38 per square foot on ADUs of 500 square feet or more (GUSD developer fees): 800 × $5.38 = $4,304. The city ordinance (D.15) confirms the owner pays school-district fees. Note the two cliffs sit at different sizes: school fees switch on at 500 sq ft, impact fees at 750. An ADU between 500 and 750 pays school fees only; at 800, it pays both.
Water and sewer: $0, in writing. The ordinance (Sections D.17–20) states that an ADU “shall not be considered a new residential use for purposes of calculating connection fees or capacity charges for utilities, including water and sewer” — unless built together with a new single-family dwelling. Share the existing service and the connection-fee line is $0 by ordinance, not by practice. (A separate meter or new connection can still be charged proportionally under Gov. Code §66013, but that is a choice, not the default.)
ADU review and covenant: $1,005. Planning’s ADU review runs $475 and the required Covenant & Agreement recording runs $530 (both FY 2026-27). Small lines, but they are pure Glendale — not every city itemizes them.
Design and engineering: $14,000 (carried, with relief available). The series-standard design line. Glendale operates a Standard ADU Plan Program — pre-approved Standard Plans 1, 2, and 3 for expeditious review — but the plans are owned by private firms and sold, not free, so we keep the full line in the model. Note the elegant detail: Standard Plan 1 is 740 sq ft, which slides under the 750 sq ft impact-fee exemption. The program’s own flagship design appears to dodge the city’s own cliff.
The 50 square foot cliff
| Fee at 800 sq ft | Glendale | Notes |
|---|---|---|
| Parks and Library DIF | $0 – $4,700 | Main-house proportional, capped |
| Quimby fee | Unconfirmed | Ordinance silent; not in total |
| School district developer fees | $4,304 | GUSD, unaffected by the 750 rule |
| Water / sewer capacity charges | $0 | Ordinance: not a new residential use |
Glendale’s cliff is the narrowest in the series and the most unavoidable. In San Diego the cliff spans hundreds of square feet of design freedom; in Glendale it is 50. The ordinance allows 800 and exempts 749 — there is no compliant detached design between the exemption and the maximum that meaningfully changes the fee outcome. If you want the DIF line at $0, you build at 749 or below; at 800, you pay whatever the main-house proportion yields, up to $4,700.
Starting 2027-01-01, SB 1117 changes the statewide rule so impact fees on the first two ADUs apply only to square footage above 750 — which would shrink Glendale’s already-narrow cliff to the 50 sq ft sliver itself. The city’s 2022 ordinance predates the law and will need updating; flagged for the December quarterly re-verification.
What moves the number most in Glendale
1. The valuation the plan checker assigns. The $8,550 permit-and-review figure swings directly with valuation — and Glendale does not publish the $/sq ft table. A lower assigned valuation drops the permit, the 140% plan check, and the 50% surcharge together. Ask Building & Safety how they value detached ADUs before you budget; the formula is public, the input is a conversation.
2. Your main house’s size. The DIF line is $0–$4,700 entirely as a function of primary-dwelling square footage. Two identical 800 sq ft ADUs on different lots can owe different impact fees. Get the proportion from the fee resolution before finalizing.
3. The school fee. At $4,304 it is the largest single fee line and there is no design-around above 500 sq ft. Budget it first.
4. Whether you use a Standard Plan. The 740 sq ft flagship plan is the only pre-approved design in the series that structurally avoids its own city’s cliff. The time savings are real (expeditious review); the fee savings ($0 DIF) are arithmetic.
5. Meter strategy. $0 on shared existing service versus proportional charges on a new connection. Decide before design.
What this number does not include
| Not included in $318,000 | Typical impact |
|---|---|
| Construction loan interest | Carried 9 to 14 months |
| Property tax reassessment | Only the new construction is added (Prop 13) |
| Vacancy before first tenant | 1 to 3 months is common |
| Property management | 8% to 10% of rent |
| Quimby fee (if applicable to 750+ ADUs) | Unconfirmed — see above |
| Contingency | 10% to 15% — budget it, don’t hope |
A 12% contingency on this build is $38,160.
→ Full year-one ownership cost: ADU all-in cost in California
→ The Long Beach companion, where ADUs get their own reduced impact-fee rates: Long Beach ADU cost
Put your own quote in these six rows
We made a blank version of the six-phase ledger. Drop your contractor’s numbers into it and see which line doesn’t match ours.
Download the worksheet — CSV (import to Google Sheets), no email required
Compare any two builds side by side →
Want the regional benchmark ranges for each phase, updated quarterly?
Methodology and sources
Every figure on this page is a modeled median, not a quote. Here is exactly how it was built, so you can check it or reproduce it yourself.
| Input | Source |
|---|---|
| Building permit tiers; plan-check percentages; ADU review $475 | FY 2026-27 Citywide Fee Schedule (city) |
| DIF 750 cliff; $4,700 cap; water/sewer ordinance; 800 sq ft max | ADU Ordinance, Case No. PZC-0001-2022 (city) |
| School fees $5.38/sq ft on ADUs 500+ sq ft | GUSD Developer Fees |
| Covenant & Agreement $530; fee-study methodology | Final User Fee Study Report (city) |
| Standard ADU Plan Program (Plans 1–3) | City of Glendale ADU page |
| Standard Plan 1 = 740 sq ft | aduzoning.org (third party) |
| State ADU law: 750 sq ft impact-fee provisions | Gov. Code § 66311.5 (SB 543, eff. 1 Jan 2026) |
| SB 1117 marginal impact fees from 2027-01-01 | SB 1117 bill page |
| Construction phases 2–6 (carried from LA baseline) | 800 sq ft ADU cost — Los Angeles County · Methodology |
| Phase-level cost shares for residential construction | NAHB Cost of Construction Survey |
On the building permit. Glendale publishes the rate tiers but not the residential construction valuation table, so the $2,757 permit figure is a worked example at the $320,000 build valuation — conservative, since declared valuations typically run below contract price. The 140% plan-check stack and 50% surcharge are official multipliers applied to whatever permit fee results. If Building & Safety publishes a valuation table or confirms ADU practice, we will update this line — see Corrections.
On the DIF range. The $0–$4,700 range reflects the ordinance’s main-house proportionality with the fee-resolution cap. The soft-cost total uses the $2,350 midpoint. Quimby’s applicability to 750+ sq ft ADUs could not be confirmed from public documents and is excluded from the total.
On the construction phases. Glendale’s agencies do not publish phase-level construction costs, and we located no public Glendale permit-valuation dataset for ADUs. Phases two through six are therefore carried unchanged from the Los Angeles County baseline rather than adjusted by an unanchored regional factor. If you hold Glendale permit valuations or contractor data, we want them — see Corrections.
Check this number against your own address
- Ask Building & Safety how they value detached ADU construction ($/sq ft) — the single biggest input to the permit line.
- Ask which Parks and Library DIF amount applies at your main house’s square footage — get the proportion in writing.
- Confirm whether the Quimby fee applies to ADUs over 750 sq ft.
Declared valuations run below contract price — treat them as a floor, not a total. Full detail on Methodology.
If your local numbers diverge meaningfully from ours, we want to know. See Corrections.
Our position
We don’t build ADUs. We don’t sell plans. We don’t sell your information to contractors. No figure on this site has been paid for or reviewed by anyone whose costs we publish. More on About.
Figures are Glendale, 2026, stated as medians of contractor ranges. Costs vary by site conditions and finish level. The building-permit figure ($2,757) is a worked example at the stated $320,000 valuation — Glendale does not publish its residential $/sq ft valuation table. The DIF line ($0–$4,700) varies with main-house size; the total uses the midpoint. Quimby applicability is unconfirmed and excluded. This is construction cost information — not a quote, and not legal, engineering, or financial advice. Confirm requirements with the City of Glendale Community Development Department and a licensed California contractor.
Frequently asked questions
How much does an ADU cost in Glendale in 2026?
About $318,000 for an 800 sq ft detached, single-story, new-construction unit with mid-grade finishes in Glendale — roughly $398 per square foot. That is our modeled median: the soft-cost phase is rebuilt from the city’s official fee schedule and ADU ordinance, while construction phases are carried from the Los Angeles County baseline because Glendale does not publish phase-level construction costs.
Does Glendale charge impact fees on ADUs?
Only at 750 square feet and above. Under 750, ADUs are fully exempt; at 800, a Parks and Library fee applies in proportion to the main house, capped at $4,700. Because the ordinance caps detached ADUs at 800 sq ft, the maximum-size ADU always pays.
How much are ADU permit fees in Glendale?
It depends on the valuation the city assigns — the rate tiers are public but the $/sq ft valuation table is not. Worked at the $320,000 build valuation, the building permit is about $2,757, plan check across four departments adds 140% (about $3,860), and the program surcharge adds another 50% of plan check (about $1,930).
Do I pay school district fees on an ADU in Glendale?
Yes — $4,304 on 800 sq ft, tied with Long Beach for the highest in the series. GUSD charges $5.38 per square foot on ADUs of 500 square feet or more.
Does Glendale have pre-approved ADU plans?
Yes — the Standard ADU Plan Program offers pre-approved Plans 1, 2, and 3 for expeditious review. Plans are sold by their private designers, not free. Notably, Plan 1 at 740 sq ft falls under the 750 sq ft impact-fee exemption.