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

What you can build in Torrance

On a single-family lot in Torrance you may build a combination of one ADU plus one JADU under the local ordinance, and up to three units (a conversion ADU, a new-construction detached ADU at the state floor, plus a JADU) under the state-law stack at Gov. Code § 66323. The rules below cover the most common case: a single-family detached or attached ADU under the state-law and local framework that applies to most R-1 zoned Torrance properties.

Size limits

An attached or detached ADU in Torrance can be up to 1,000 square feet under TMC § 92.2.10 (Ord. O-3954, October 2025). Two narrower pathways sit alongside it: the statewide-exemption Building Permit Only pathway (Gov. Code § 66323) guarantees an 800-sqft detached ADU by right, and in the Hollywood Riviera Coastal Zone state ADU law governs directly (per Gov. Code § 66329), allowing up to 1,200 sqft for a 2+ bedroom ADU at the coastal 16-ft height. An attached ADU may not exceed 50% of the primary dwelling’s livable area (Gov. Code § 66321(c)(2)). JADUs are capped at 500 sqft per TMC § 92.2.11 and Gov. Code § 66333. The minimum permitted size for any ADU is 150 sqft per state efficiency-unit standards.

Critical state-law floor: Gov. Code § 66321(b)(2) provides that no local rule — setbacks, lot coverage, open space, FAR, percent-based caps, or aesthetic standards — may prevent construction of an 800-sqft ADU at 16 feet with 4-foot side and rear yard setbacks. On Torrance lots where the underlying R-1 zoning open-space, FAR, or coverage rules would otherwise narrow the buildable envelope, this state-law floor is the operative protection — the city cannot reduce the buildable envelope below an 800-sqft, 16-ft, 4-ft-setback ADU. Torrance’s local cap sits well above that floor: detached ADUs may reach 1,000 sqft and 23 feet (two stories) citywide.

Setbacks

Side and rear setbacks are 4 feet for all new-construction detached ADUs per TMC § 92.2.10, matching the state floor at Gov. Code § 66314(d)(7). The front setback defaults to the underlying R-1 zoning district’s requirement (typically 15–25 feet in Torrance R-1). No setback is required for an ADU built within an existing structure or in the same location and dimensions as an existing structure (Gov. Code § 66314(a)(1)(D)). Detached ADUs must maintain a minimum building separation from other buildings on the lot per the underlying building code.

Maximum height

Under Ord. O-3954 (October 2025), TMC § 92.2.10 sets detached ADU height at 18 feet for one story and 23 feet for two stories citywide. The 16-foot height applies only in the Hillside Overlay and the Hollywood Riviera Coastal Zone. Attached ADUs may reach 18 feet (one story) or 25 feet (two stories). These meet or exceed the state-law floor at Gov. Code § 66321(b)(4), which guarantees at least 16 feet for any detached ADU and 18 feet within one-half mile of a major transit stop (in Torrance, the Torrance Transit Center on Crenshaw Boulevard and the Metro J Line corridor).

The 23-foot two-story allowance is what makes Torrance a genuine two-story ADU market — not just a single-story one. CALI ADU’s two-story Signature Homes are designed to a roof ridge of roughly 21 to 22 feet, comfortably under the 23-foot cap. That makes the Fairfax (840 sqft, two bedrooms) buildable as a free-standing detached ADU on a flat R-1 Torrance lot — a full two-bedroom home on a 14-by-32-foot footprint, where a single-story plan of the same square footage would take up far more of the yard. The larger two-story Venice (1,080 sqft) and Culver (1,200 sqft) exceed Torrance’s 1,000-sqft ADU cap, so on a standard lot they belong in cities with a higher size ceiling.

Parking

One off-street parking space per ADU is the default requirement under TMC § 92.2.10, mirroring the state framework at Gov. Code § 66323(c). In practice, almost no Torrance ADU project actually has to add parking, because state law waives the requirement under any of five exemptions:

• The ADU is within one-half (½) mile walking distance of public transit;
• The ADU is within an architecturally and historically significant historic district;
• The ADU is part of the existing primary dwelling or any existing accessory structure;
• The ADU is in an area where on-street parking permits are required but not offered to ADU occupants; or
• The ADU is within one block of a city-approved and dedicated car-share parking space.

Most Torrance addresses qualify under at least the transit-proximity exemption — the Torrance Transit Center on Crenshaw Boulevard, the Metro J Line silver corridor, and the city’s major bus routes (Torrance Transit and LA Metro lines along Hawthorne, Western, Crenshaw, Sepulveda, and Pacific Coast Highway) cover most of the city within the half-mile radius. Garage-conversion ADUs get a separate guarantee: Gov. Code § 66323(c)(2) prohibits the city from requiring replacement parking when an existing garage, carport, or covered parking structure is demolished to build the ADU or converted into the ADU. JADUs require no parking under any circumstance per Gov. Code § 66333.

Owner-occupancy

Owner-occupancy is not required for a standard ADU on a single-family lot in Torrance. Gov. Code § 66315 prohibits a local agency from imposing an owner-occupancy requirement on an ADU for permits issued before January 1, 2025, and HCD’s September 5, 2024 letter specifically flagged the prior Torrance ordinance language requiring owner-occupancy on lots with both an ADU and a JADU as preempted by state law. Ord. O-3954 addressed those findings.

JADU owner-occupancy changed materially on January 1, 2026 via AB 1154 (codified at Gov. Code § 66333(b)). The owner-occupancy requirement now applies only when the JADU shares sanitation facilities (a bathroom) with the primary dwelling. A JADU with its own dedicated, separate bathroom is no longer subject to owner-occupancy. AB 1154 also expressly exempts ADUs and JADUs owned by another governmental agency, land trust, or housing organization from any owner-occupancy mandate — an issue HCD flagged in its September 2024 letter as missing from Torrance’s prior ordinance language.

Impact fees

ADUs under 750 square feet of livable interior space are exempt from all local impact fees — school district fees, park-and-recreation fees, water and sewer connection fees, and any other fee normally tied to new residential construction (Gov. Code § 66318). This is a state-law protection Torrance cannot override. ADUs over 750 sqft are subject to impact fees charged proportionally to the size of the ADU relative to the primary dwelling — not at the full per-unit rate that would apply to standalone new construction.

City building-permit fees and plan-check fees are separate from impact fees. They apply to ADUs at any size. City of Torrance building-permit and plan-check fees are valuation-based — set from the construction valuation rather than a flat ADU rate — and are passed through at cost in a CALI ADU contract. A Hollywood Riviera Coastal Zone project carries an added Coastal Development Permit fee paid to the city and the California Coastal Commission.

Design rules — entryway visibility and covered entries

TMC § 92.2.10 carries two Torrance-specific design rules worth flagging early. First: ADU entryway doors may not face toward a public right-of-way unless the door is set back at least 10 feet from the right-of-way. Second: a covered entryway is required for any type of ADU. The covered entry must match the architectural style of the ADU and must not be visible on the same architectural elevation as the main entrance door to the primary dwelling. Both rules are objective and enforced at plan check; neither is a deal-breaker for any of the nine Signature Homes, but both shape the site plan and elevation orientation. We work through both rules during design as part of every Torrance Backyard Review.

Permitting timeline

State law requires the City of Torrance to act on a complete ADU or JADU permit application within 60 days of submittal (Gov. Code § 66317). The 60-day clock starts when the city deems the application complete and pauses while the applicant responds to plan-check corrections. SB 543, effective January 1, 2026, added a separate 15-business-day completeness determination deadline: if the city does not issue an incomplete-application letter within 15 business days of submittal, the application is deemed complete by operation of law (Gov. Code § 66317(a)(2)). Together these deadlines cap the realistic in-house permit timeline at roughly 90–120 days for a clean application. Torrance’s Pre-Approved ADU Program shortens the front end of this timeline for projects using a pre-approved plan set.

Torrance’s Hillside Overlay and ADU design review

The Torrance Hillside Overlay was adopted by the City Council in 1977 to govern hillside and coastal development. It covers the sloped lots along the city’s southwest edge — the Hollywood Riviera and parts of the adjacent Pacific Coast Highway frontage — and a small handful of other elevated parcels. For most Torrance ADU projects on flat R-1 lots in West Torrance, Southwood, the Old Torrance grid, and the Walteria neighborhood, the Hillside Overlay does not apply.

Where the Hillside Overlay does apply, it adds objective design standards (grading, retaining walls, view corridors, drainage) layered on top of the underlying R-1 zoning and the ADU ordinance. State ADU law preempts most discretionary review for qualifying projects (Gov. Code § 66317(a)(1) requires ministerial-only approval), so the Hillside Overlay rules operate as objective constraints — not as a discretionary review veto. A qualifying ADU permit application still moves through the 60-day ministerial clock; the Hillside Overlay just adds documentation and site-plan requirements at submittal.

The combination of the Hollywood Riviera Coastal Zone and the Hillside Overlay on the same lot is where ADU projects in Torrance get materially more involved. Drainage, grading, view-corridor, and retaining-wall analysis all come into play, and CDP review is concurrent. We work through Hillside Overlay requirements as part of every Hollywood Riviera Backyard Review.

The end-to-end permit process and timeline

ADU permits in Torrance are issued ministerially by the Building & Safety Division of the Community Development Department (3031 Torrance Boulevard) — no hearing, no design review, no council vote. Once an application is complete, the city must approve or deny it within 60 days or it is deemed approved (Gov. Code § 66317), and a 15-business-day completeness-determination deadline applies on the front end (Gov. Code § 66317(a)(2)).

Because every Signature Home is pre-engineered, the path is short and predictable. Plan on about two weeks to prepare and finalize your Signature plan set for your lot — including the TMC § 92.2.10 entryway and covered-entry design rules — the 15-business-day completeness check, and the 60-day ministerial approval window. Plan check is a conformance review of drawings that are already engineered, not a from-scratch evaluation. Building from the Torrance Pre-Approved ADU Program shortens the front end further. Construction then runs 4 to 6 months depending on the model’s size, for about 6 to 9 months start to finish. (Custom designs run longer, because the city is seeing the drawings for the first time.)

The Hollywood Riviera Coastal Zone is the one overlay that adds to that baseline. A project there needs a Coastal Development Permit reviewed concurrent with the building permit, typically landing 2 to 4 months from submittal (more where view-corridor or drainage analysis applies on sloped lots). The construction schedule is written into your fixed-price contract — if we go past it, we pay you a daily delay penalty until we hand you the keys — and we handle all permit processing, CDP coordination, plan-check correspondence, and agency clearances as part of every Signature Home project. The covenant required at TMC § 92.2.10 is drafted to the City Attorney’s approved form and recorded with LA County before final building inspection.

Long-term rental income in the South Bay

TMC § 92.2.10 sets a 30-day minimum tenancy for any ADU rental in Torrance — the same 30-day floor permitted by state law (Gov. Code § 66317(d)). Short-term rentals under 30 days are not permitted from an ADU regardless of the city’s broader STR regulations. Long-term rental is the operative business case.

Long-term ADU rental returns in Torrance are strong but vary by neighborhood. As a baseline, HUD’s FY2026 Fair Market Rents for the Los Angeles–Long Beach–Glendale area (effective October 1, 2025) are $2,085 for a one-bedroom, $2,601 for a two-bedroom, and $3,298 for a three-bedroom; a new, well-finished Torrance ADU typically rents above those figures. One-bedroom ADUs in West Torrance and Southwood typically command $2,400–$3,200 per month for a well-finished 1BR Sunset or 1BR Westwood. Two-bedroom ADUs in the same neighborhoods command $2,800–$3,800 per month for a Melrose-class build. Hollywood Riviera ADUs with proximity to the beach command a meaningful premium — a Lincoln 3BR in the Hollywood Riviera flats can clear $4,500–$5,500 per month. Plan around long-term rental as the base case; a 2BR Melrose at $329K all-inclusive plus permit fees, earning $3,300/month at 95% occupancy, yields roughly an 11.4% gross rental return before financing — with the ADU adding measurable resale value on top of the income stream.