Building an ADU in La Verne. Rules, costs, timeline.

Can I build an ADU in La Verne?

Five things to know before you start

If you read nothing else on this page, read these. They are the five points that change the most La Verne projects.

Number of units per parcel

This is where La Verne’s ordinance is easy to misread. § 18.120.045.B opens with “only one accessory dwelling unit or one junior accessory dwelling unit shall be allowed on a residentially zoned lot” — and then adds “unless otherwise permitted in accordance with Section 18.120.060.” That section is the one that matters. It requires the City to ministerially approve any combination of the following on a single-family lot:

That is three accessory units on top of your existing house — the same stack Gov. Code § 66323(a)(1)–(2) and the HCD ADU Handbook require every city to allow. On a lot with an existing apartment building the list changes: conversions of up to 25% of the existing units in non-livable space, plus up to eight detached ADUs, never more than the number of existing units (§ 18.120.060.C–D; Gov. Code § 66323(a)(3)–(4)).

Owner-occupancy

You do not have to live on the property to build or rent an ADU. The April 2026 rewrite says so twice: the City “shall not enforce any owner/occupancy requirement previously imposed on an accessory dwelling unit” and “no accessory dwelling unit shall be subject to an owner-occupancy requirement” (LVMC § 18.120.080.C.1–2), which is what Gov. Code § 66315 requires. A junior ADU is the one exception, and a narrow one: after AB 1154 (effective January 1, 2026, amending Gov. Code § 66333(b)) the requirement reaches only a JADU that shares a bathroom with the main house, and La Verne’s text now says exactly that (§ 18.120.070.D.2). Give the JADU its own bathroom and owner-occupancy no longer applies. The JADU still records a deed restriction against separate sale, enlargement past 500 sqft, and rentals under 31 days (§ 18.120.070.H).

What an ADU costs in La Verne (2026)

Our Signature plans are fixed-price — architectural design and full permit processing included, the same number whether the lot is in La Verne, Claremont, or the Valley. Construction is separate: once your plans are permitted, you build it yourself, bring your own licensed contractor, or build with one of our vetted construction partners. The figures below are the estimated cost to build each plan with an independent licensed general contractor. Here are the plans that permit in La Verne:

Only plans that permit in La Verne as drawn are listed. Our three two-story detached Signature Homes are not shown because a freestanding two-story ADU exceeds the 16 to 18 ft detached limit here. The Garage + ADU Above is the plan for the 25-ft garage-top allowance.

What is fixed is the plan: our Signature plan fees run $7,490 to $12,990 — architectural design and full permit processing included. We can state it because our Signature Homes were engineered to pass the objective standards in LVMC § 18.120.050 on paper. The build figures above are an estimate by an independent licensed general contractor, roughly $180K–$350K across the plans that permit in La Verne — your plans, your choice of builder: build it yourself, bring your own contractor, or use one of our vetted construction partners.

Not in either number: the City’s fees, utility connection charges, and any impact fee on a unit above 750 sqft. Your Backyard Review includes a line-item estimate of those pass-through costs for your specific lot.

For sizing and payback math: try our ADU calculator and the ROI calculator.

City fees and impact fees

La Verne’s ADU permit runs in two steps, and each has its own fees. The planning entitlement, on the City’s own ADU application sheet, is $0.50 per square foot of the unit, plus a $55 records-management charge and a $25 environmental determination — $480 for an 800 sqft unit. Building-permit and plan-check fees follow at Building & Safety and are set by council resolution (§ 18.120.030.C), based on project valuation rather than on the fact that you are building an ADU.

Impact fees are different. State law bars any impact fee on an ADU of 750 sqft or less of interior livable space, and above that line the fee must be proportionate to the size of the main house (Gov. Code § 66311.5(c)(1), as amended by SB 543 effective January 1, 2026). La Verne’s text says “less than 750” (§ 18.120.050.K.1); at exactly 750 sqft the state wording controls. A JADU of 500 sqft or less is exempt as well, and a unit under 500 sqft is not assessable space for school fees (§ 66311.5(c)(3)).

Utility connection fees and capacity charges follow the same shape: none for a conversion inside the house, proportionate to the unit’s size or fixture count for everything else, and none at all on a permit that legalizes a pre-2020 unit (§ 18.120.050.J). A JADU is not a new dwelling unit for water, sewer or power connection purposes (§ 18.120.070.I).

What it returns

La Verne bars rentals under 31 days, so the ADU is a long-term rental asset, a multigenerational space, or a home office. The trusted benchmark for the first of those is HUD’s Fair Market Rent for the Los Angeles–Long Beach–Glendale metro area (FY 2026, revised effective May 21, 2026). Those figures are metro-wide across all housing stock and ages, so read them as a floor: a new, fully permitted detached ADU in an established single-family neighborhood typically rents at or above them.

A studio-to-one-bedroom unit maps onto the first two rows, a two-bedroom onto the third, and a three-bedroom onto the fourth. The full lineup with build costs is in the cost table above. For payback math keyed to your lot and financing, use the ADU ROI calculator.

HUD FMR figures: FY 2026 Fair Market Rents, Los Angeles–Long Beach–Glendale HUD Metro FMR Area, as revised effective May 21, 2026 (huduser.gov; 91 FR 21301, Apr. 21, 2026). They are a benchmark, not a forecast. Your ADU’s performance depends on finish level, lot, access, parking, and the rental market at the time you lease it.

Why the market rewards it here

• The lots are big. The standard P-R single-family lot is 7,500 sqft with a 25-ft rear setback on the house (§ 18.36.050). After the 4-ft ADU setbacks and the 10-ft separation there is usually room for a 1,000 sqft single-story unit and its 400 sqft outdoor area.
• The A Line changed the height math. Lots within a half-mile walk of the La Verne/Fairplex station get 18 ft plus a pitch allowance, and no parking requirement at all. That is a larger, cheaper unit on the same footprint.
• The repeat-plan lane is real. A plan identical to one the City has already approved this code cycle gets a 30-day decision (Gov. Code § 65852.27(b); § 18.120.030.B.5). Every Signature Home that clears La Verne once clears it faster the next time.
• No owner-occupancy, no discretion. The ordinance now says both, in writing. If the plan meets § 18.120.050 on paper, the community development director approves it (§ 18.120.040.A). No design review, no neighbor appeal path.
• State law backstops the City. Gov. Code §§ 66310–66342 set the floor; the 60-day clock under § 66317 runs; and the 800 sqft unit is protected whatever the local standard says.

When an ADU isn’t the right move

Not every La Verne property is a good ADU candidate, and it is cheaper to learn that now than after you have paid for plans. Four situations where we would tell you to wait, choose a different unit type, or not build at all:

• Your numbers depend on short-term rental income. They will not work. Every ADU and JADU must be rented for at least 31 days (§ 18.120.080.B), and the City’s short-term rental permit does not reach accessory units. Run the math on a 31-day-plus tenancy or reconsider.
• You want a freestanding two-story unit. On its own footprint it is capped at 16 ft, or 18 ft near the station. The two-story paths are attached to the house or a single level over a detached garage. If neither fits your lot, a large single-story plan is the honest answer.
• You want 1,000 sqft on a shallow lot. Above 800 sqft the 400 sqft outdoor-living rule, the 10-ft separation and the rear-building-line siting rule all apply. On a lot that cannot absorb them, the protected 800 sqft unit delivers more value than fighting for the extra 200.
• You need to sell the unit on its own. La Verne has not opted into AB 1033, so an ADU-as-condo exit is not available here. The only separate-sale route is the nonprofit one at Gov. Code § 66341, which almost no homeowner qualifies for.

The rules that make La Verne different

The garage-top ADU

Most eastern San Gabriel Valley cities stop a detached ADU at 16 or 18 ft. La Verne adds a fourth figure: an ADU “may be built on top of a detached garage; provided that the garage is maintained for parking and the total height of the structure does not exceed 25 feet” (§ 18.120.050.B.4). The conditions are the rule. The garage must be detached, it must stay a garage, and a declaration saying so is recorded against the property. The 4-ft side and rear setbacks still apply to a unit above a garage (§ 18.120.050.D.2), and the 25-ft total leaves room for one level of living space over the parking level — B.6 caps the ADU at two stories, but it is the total height that binds.

On a lot where the garage sits at the back corner, this is the best use of the footprint in the city: the parking stays, the yard stays, and the unit gets the view. We have a standardized plan for it — the Garage + ADU Above, a new two-car garage with a studio or one-bedroom home above it, permitted as one structure — and we confirm the 25-ft total against your lot and roof pitch before it is submitted.

The 400 sqft outdoor-living rule and the 10-ft separation

These two standards are where La Verne is most demanding above 800 sqft. Each unit in a single-family zone needs its own 400 sqft landscaped outdoor area, at least 15 ft in every direction, that does not overlap the driveway, the parking, or the main house’s front and rear setback areas (§ 18.120.050.F). A detached ADU must also sit 10 ft from every other building on the lot (§ 18.120.050.D.5) — and the zoning code explains why: an accessory structure less than 10 ft from the main house is treated as part of it (§ 18.36.032.C.4).

Both are waived for the 800 sqft unit by § 18.120.050.C.3. The outdoor-living rule is the kind of open-space standard Gov. Code § 66321(b)(3) says cannot block that unit, and a detached state-stack unit is exempt from the separation rule as well (Gov. Code § 66323(b)). Above 800 sqft, budget for them in the site plan from day one; they decide where the unit goes more often than the setbacks do.

The design-match standard, and what it can and cannot require

§ 18.120.050.H.1 asks for the “exact same architectural style” as the main house — roof, windows, doors, wall materials and color. Gov. Code § 66314(b)(1) lets a city set objective design standards. Matching a roof pitch and a siding material is objective. “Architectural style” is not: HCD’s Handbook (March 2026, p. 34) names “must maintain similar architecture style” as a subjective standard a city may not impose (Gov. Code § 66313(i)), and a planner cannot deny a ministerial permit on it. We design to the letter of H.1 on units above 800 sqft, cite § 18.120.060.B and Gov. Code § 66323(b) on a detached unit at or below it, and have not found a La Verne house style the Signature lineup cannot match.

The City’s own application guide is behind the ordinance

The first document a La Verne homeowner finds is the City’s Planning Development Application for an ADU or Junior ADU Permit. It is a good checklist — it is where the $0.50-per-sqft fee, the color elevation and the ownership verification come from. But it still promises a completeness determination “within 30 calendar days of the application submission date.” The ordinance the same sheet links to says 15 business days (§ 18.120.030.A), and so does Gov. Code § 66317(a)(2)(A) since January 1, 2026. Hold the City to the shorter clock.

Mills Act properties and Old Town

La Verne’s historic core around the University of La Verne and the old Lordsburg townsite holds much of the Craftsman and bungalow stock in the city, and some of it sits under a Mills Act contract. If yours does, the ADU must comply with the contract’s standards, including the Secretary of the Interior’s Standards, and the contract itself must be amended to authorize the unit (§ 18.120.050.L). The offset is parking: a Mills Act property owes none for the ADU (§ 18.120.050.G.6.b). Check the contract before you design; it changes the drawing set more than the ordinance does.

Legalizing a unit built without permits

If your property already has a converted garage or a back house built before January 1, 2020 without permits, La Verne cannot deny a permit to legalize it on the grounds that it violates the building code or the ADU chapter — only where fixing the problem is necessary under Health and Safety Code § 17920.3 (§ 18.120.080.E.2; Gov. Code § 66311.7). You may commission a confidential third-party inspection first, the City may not penalize you for having the unit, and no impact, connection or capacity fee applies to that permit (§ 18.120.080.E.3–4; § 18.120.050.J.3, K.4). Until 2030, a notice to correct an ADU building-standard violation must tell you that enforcement can be delayed five years if it is not needed for health and safety (§ 18.120.080.G).

Where the local code still conflicts with state law

Ordinance 26-1142 fixed most of what HCD would have flagged in the old chapter — owner-occupancy, the unit stack, the eight-unit multifamily count, JADU sanitation. Five points remain where the local text is narrower than Gov. Code §§ 66310–66342 or the HCD Handbook, and state law preempts (Gov. Code § 66316):

None of these is a reason to avoid La Verne. They are the five sentences we put in the pre-application letter so the plan checker and the homeowner start from the same reading.