Building an ADU in Torrance. Rules, costs, timeline.

Can I build an ADU in Torrance?

Five things to know before you start

If you read nothing else here, read these. They are the five points that change the most Torrance projects.

How many units a Torrance lot allows

Table 92.2.10-1 sets the baseline: one detached ADU or one attached ADU, plus one junior ADU. Read alone, that looks like a two-unit ceiling. It is not the whole rule. The table carries a footnote pointing to the exempt-unit track at § 92.2.10(G)(1), and that track covers three separate things.

• An ADU carved out of existing space. Inside the house or an accessory building, with up to 150 extra square feet for ingress and egress (G.1.A.i).
• A junior ADU. Entirely within the square footage of the house, up to 500 sqft (G.1.A.ii).
• A new detached ADU. Up to 800 sqft, 4-foot side and rear setbacks, 16 feet or more as Gov. Code § 66321 allows (G.1.B).

Gov. Code § 66323(a)(1)–(2) requires a city to allow those to be combined on one single-family lot, and the HCD ADU Handbook says the same. So the working answer is three accessory units alongside the house you already have.

Multifamily lots

A lot with an existing multifamily building can carry detached ADUs matching the number of existing units, up to a maximum of eight (Table 92.2.10-1; TMC § 92.2.10(G)(2)(B)(ii)(2)). That tracks the state ceiling at Gov. Code § 66323(a)(4)(A)(ii), raised to eight by SB 1211. A proposed multifamily building gets up to two. Separately, you may convert non-livable space — storage, boiler rooms, passageways, attics, basements, garages — into ADUs equal to 25 percent of the existing units, with a minimum of one. Junior ADUs are a single-family product only.

Owner-occupancy

Not required for an ADU. Gov. Code § 66315 bars a city from imposing one, and § 92.2.10 imposes none. The junior ADU is different, and the local text is now behind the law. TMC § 92.2.10(F)(1)(C) requires a recorded covenant stating the junior ADU is legal only while the owner occupies either the house or the junior unit. AB 1154 narrowed that as of January 1, 2026: under Gov. Code § 66333(b), owner-occupancy applies only where the junior ADU shares sanitation facilities with the house. Give the junior ADU its own bathroom and the requirement falls away under state law, even though the local covenant language has not been rewritten yet.

What an ADU costs in Torrance (2026)

Plan pricing does not vary by neighborhood. The fee covers architectural design, structural engineering, Title 24 energy compliance, and every piece of permit processing and plan check correspondence through to an issued permit. Once the plans are permitted you arrange construction — build it yourself, bring your own licensed contractor, or build with one of our vetted partners.

The build estimate covers labor and materials, interior finishes, cabinetry, countertops, flooring, fixtures, appliances, and utility connections for water, power, sewer and gas. What sits outside it: City of Torrance permit and plan check fees, Coastal Commission fees on a Hollywood Riviera project, and site-specific work such as grading on a Hillside Overlay lot, retaining walls, long utility runs or drainage work near a slope. We identify and price all of that in the proposal before you commit.

City fees

Torrance assesses its fee at the building permit application, and TMC § 92.2.10(C)(14) is specific about what it buys: plan review, permit processing, development impact mitigation, and a full written set of comments listing anything defective or deficient with a description of how to fix it — all inside the 60-day window. Building permit and plan check fees are valuation-based, set from construction valuation rather than a flat ADU rate, so they scale with the size of what you build. The City publishes its current schedule; we pass these through at cost.

Impact fees are the part state law controls. An ADU under 750 square feet is exempt outright (Gov. Code § 66311.5(c)(1)), and one under 500 square feet is also outside school impact fees (§ 66311.5(c)(3)). At 750 square feet and above, impact fees must be charged in proportion to the ADU’s size relative to the primary dwelling, not at the full rate a new house would pay. Torrance cannot override any of that.

What it returns

Long-term tenancy is the only option here. TMC § 92.2.10(B)(1) bars renting an ADU for less than 30 days, and state law sets the same floor for exempt-track units (Gov. Code § 66323(e)) and junior ADUs (§ 66333(g)).

For a government benchmark, HUD publishes Fair Market Rents for the Los Angeles–Long Beach–Glendale metro area. The FY2026 figures as revised, effective 21 May 2026, are $2,079 for a studio, $2,328 for a one-bedroom, $2,903 for a two-bedroom and $3,681 for a three-bedroom. Read those as a floor rather than a forecast: they cover the whole metro across all housing stock and ages, including units decades older than anything you would build. A new, well-finished detached ADU typically rents above them, and Torrance’s school districts, employer density around the Del Amo corridor, and South Bay location support that. Run your own numbers on our ADU ROI calculator.

When an ADU isn’t the right move

A guide that never says “not you” is a brochure. Four situations where a Torrance ADU is the wrong call, or the wrong call right now.

• Your plan depends on nightly rental income. The 30-day minimum in § 92.2.10(B)(1) is not a technicality and it is not waivable. If short-term rental is the business case, there is no version of this that works.
• You are counting on selling the unit separately. Torrance has not opted in under AB 1033. Until it does, an ADU here cannot be sold as a condominium. If your exit depends on that, you are planning around a policy change that may not come.
• You need it finished in under six months. Design through move-in runs roughly six to nine months on a Signature plan and longer on a custom one. A family situation that needs housing sooner is better served another way.
• Your lot is in the Coastal Zone and you wanted two stories. Hillside Overlay and Coastal Zone lots are capped at 16 feet over one story (E.4.A.i.1). The Hollywood Riviera view that makes the lot desirable is the same reason the envelope shrinks.

The rules that make Torrance different

The design standards

Most city ADU ordinances say little about how the unit looks. Torrance says a great deal, and all of it is objective, which means it is checked at plan check rather than argued at a hearing. Section 92.2.10(E)(8)(A) requires a covered entryway on every ADU, matching the unit’s architectural style and not visible on the same elevation as the house’s front door. Entry doors may not face a public right-of-way unless set back at least 10 feet.

• New balconies, roof decks and decks more than 2 feet above grade are prohibited, as are full-height window or door openings with a guardrail.
• New mezzanines, lofts and balcony-form intermediate levels are prohibited.
• New stairways must be fully enclosed inside the structure and must not be visible from the public right-of-way.
• Architecture, exterior materials, finishes and color must match the primary dwelling on the lot.
• Roof form and pitch must match the primary residence, or stay consistent with its architectural style.
• Every building frontage needs at least two materials, one covering at least 20 percent, plus at least two exterior colors.
• No facade may run 20 feet in a continuous plane without a window, door, plane change or vertical element.

None of these is a deal-breaker for a well-designed unit. All of them shape the elevation, and several shape the floor plan. The enclosed-stairway rule in particular changes how a two-story ADU is laid out.

The Torrance Tract Overlay

If your parcel holds a contributing or altered-contributing residential structure identified in the City’s Historic Resources Survey and sits within the Torrance Tract Overlay, the proposal must also be consistent with the Torrance Tract Design Guidelines (E.8.A.x). That is a second design layer on top of the list above, and it applies to the older grid around Old Torrance. It is worth confirming your parcel’s status before you settle on a style.

The Hillside Overlay and the Hollywood Riviera Coastal Zone

Hollywood Riviera sits at the city’s southwest corner, next to Palos Verdes Estates, and falls inside the California Coastal Zone. Together with the Hillside Overlay it is the one part of Torrance where the ADU envelope narrows: a detached unit is capped at 16 feet over one story rather than 23 feet over two, though Gov. Code § 66321 can require more. Attached units keep the 18 and 25 foot allowances (E.4.A.i).

The size cap does not change. One thousand square feet applies citywide, in the Coastal Zone as everywhere else. What changes is the permit: TMC § 92.2.10(C)(7) requires the Coastal Commission approval to be filed with the building permit application, and as of AB 462 that review runs concurrently on its own 60-day clock.

Rental term and separate sale

Torrance writes the 30-day minimum into the definitions themselves: § 92.2.10(B)(1) for ADUs, (B)(2) for junior ADUs, and again in the recorded covenant at (F)(1)(D). Short-term rental is not a gray area here.

On separate sale, the ordinance bars selling a junior ADU apart from the house (F.1.A), and Torrance has adopted no AB 1033 condominium opt-in under Gov. Code § 66342. Table 92.2.10-1 does recognize lots with two or more detached units under separate ownership, qualifying under Gov. Code §§ 66340–66341 — but that is a narrow pre-existing condition, not a route to selling a new backyard unit.

Two provisions worth knowing

Torrance will not deny an ADU permit because of nonconforming zoning conditions, building code violations or unpermitted structures that do not threaten health and safety and are not affected by the ADU work (C.12). You still have to fix anything that does threaten health and safety. Separately, no ADU or junior ADU is permitted at all on a property developed under TMC § 92.29.34 (D.1) — if your lot has been through an urban lot split, check that first.