Studio ADU plans. The Wilshire — 400 sqft, fixed at $219,000.
The most efficient unit type in California's ADU lineup. The Wilshire is the only model in our 9-home lineup designed end-to-end as a studio — 400 sqft, impact-fee-exempt under Gov. Code § 66318, and the most accessible price point we offer.
Studio ADU floor plans we’ve designed
The Wilshire is CALI ADU’s 400 sqft Studio/1BA Signature Home — fixed-price at $219,000 all-inclusive. Browse the floor plan and every exterior style variant below.
The Wilshire — 400 sqft Studio/1BA
Open living and kitchen, separated sleeping alcove, full bathroom, and a private entrance with covered porch. 9-10 ft ceilings keep the space feeling generous despite the compact footprint. Five exterior style variants below.
$219,000 · All-inclusive fixed price · View full Wilshire model page →
Stucco Gable
Classic California stucco with a pitched gable roof. Reads naturally next to Spanish Revival or traditional homes.
Modern Farmhouse
Vertical board-and-batten siding with a clean gable. A contemporary take on the farmhouse silhouette.
Warm Vertical Siding
Stained vertical wood siding for a warmer, more natural exterior. Pairs well with Mid-Century or hillside homes.
Warm Horizontal Siding
Horizontal stained wood siding for a coastal-modern feel. Strong fit for Westside and Beach Cities lots.
Interior — Open Living
Open-plan living, dining, and kitchen with full-size appliances. Designed to feel larger than 400 sqft.
Sleeping Alcove
Sleeping area separated from the main living space by built-in cabinetry — functional separation without a wall.
Want to see studio ADUs we’ve completed? Browse the full 126-project portfolio →
On this page
What is a studio ADU?
A studio ADU is an Accessory Dwelling Unit with a single open-plan living area — sleeping, dining, and kitchen combined into one connected space — plus a separate enclosed bathroom and a private entrance. State law requires a kitchen with a cooking facility, sink, food preparation counter, and storage cabinets (Cal. Health & Safety Code § 17958.1). Beyond that, the layout is open.
Studio ADUs typically run 350-500 sqft. Below 350 sqft the unit starts to feel cramped. Above 500 sqft you're better off building a 1-bedroom (a 480 sqft Sunset or 550 sqft Westwood) for the additional separation a real bedroom provides.
The state-law minimum for any permitted ADU is 150 sqft — the threshold for an “efficiency unit” in the Health & Safety Code. No California city can require a minimum larger than that. In practice, 400 sqft is the smallest size that supports market-rate rental income.
The Wilshire — CALI ADU’s studio Signature Home
The Wilshire is the only model in our 9-Signature-Home lineup designed end-to-end as a studio. 400 sqft. Studio / 1 BA. Fixed-price at $219,000 all-inclusive.
The architectural decisions matter. A studio at this size only works if the layout makes the most of every square foot:
- 9-10 ft ceilings create vertical space that compensates for the compact footprint. Most prefab studios cap out at 8 ft.
- Sleeping alcove separated from the main living area by built-in cabinetry — functional separation without a wall.
- Full kitchen with full-size appliances (not a wet-bar kitchenette) so the unit rents at studio market rate, not as a "guest suite."
- Full bathroom with separated shower — not a half-bath or wet-room compromise.
- Private entrance with covered porch — a separate front door is required by state law and code-required for permitting.
The Wilshire — Studio Signature Home
Studio / 1 BA, 400 sqft, $219,000 all-inclusive. CALI ADU's most accessible Signature Home and the only model designed as a studio from the ground up.
Studio ADU floor plan + dimensions
The Wilshire’s footprint is approximately 20 ft × 20 ft — a square that drops cleanly onto most California single-family lots while preserving usable yard space. The interior is laid out in five functional zones:
- Open living & kitchen — ~220 sqft. Living, dining, and kitchen integrated. Hosts a full sofa, a 4-person dining table, and a galley kitchen with full-size refrigerator, range, and dishwasher.
- Sleeping alcove — ~80 sqft. Queen bed plus nightstands, separated from the main living space by built-in storage.
- Full bathroom — ~50 sqft. Shower, toilet, vanity. Located on the exterior wall for plumbing efficiency.
- Private entrance — covered porch with a small landing, a code-required separate front door, and exterior lighting.
- Storage — ~50 sqft of built-in storage (closet, mechanical, pantry).
Total: 400 sqft. The dimensions match common single-family lot rear-yard envelopes after accounting for the 4-ft side and rear setback required by state law (Gov. Code § 66314(d)(7)).
For the full Wilshire floor plan and architectural drawings, visit the Wilshire model page.
What a studio ADU costs in 2026
A custom-designed, detached studio ADU in Los Angeles typically costs $300-$500 per square foot when you add up architecture, engineering, permitting, construction, finishes, and utility connections. On a 400 sqft studio, that's a build budget of $120,000-$200,000 — before fees, before contingencies, and before the change orders that almost always show up on custom projects.
The Wilshire is fixed-price at $219,000 all-inclusive: design, engineering, permits, construction, interior finishes, appliances, and utility connections. The number in your contract is the number you pay. No change orders. No “unforeseen conditions” surcharges.
Why fixed-price beats custom on a studio specifically: at this size, every dollar of cost overrun matters more. A $30,000 custom-design overrun on a $400K project is 7.5%. The same $30,000 overrun on a $200K studio is 15%. Cost predictability is most valuable on the smallest builds.
The impact-fee exemption that makes studios pencil
California Gov. Code § 66318 exempts every ADU under 750 sqft from impact fees. Every California city must honor this exemption — it's state law, not a local courtesy.
What this saves on a studio:
- Zero impact fees. A 1,200 sqft 3-bedroom ADU pays $10,000-$30,000 in impact fees in most LA cities. A 400 sqft studio pays $0.
- Zero park fees. Same exemption covers park development fees in cities that charge them.
- Reduced school fees. California Education Code § 1760 allows school districts to charge fees on ADUs over 500 sqft; under 500 sqft, no school fee. The Wilshire at 400 sqft is exempt.
On a studio build in cities like Pasadena, Burbank, or Santa Monica, the impact-fee exemption alone often saves $15,000-$25,000. That's the difference between a studio that pencils on rental income and one that doesn't.
Where a studio ADU fits best
Studio ADUs are the right answer for several specific scenarios. Across our 126 LA County projects, these are the situations where the Wilshire keeps coming up as the best fit:
- Tight lots. The 20′ × 20′ footprint slips into the rear yard envelope on lots as small as 3,500 sqft — common in older Pasadena, South Pasadena, Burbank, and West LA neighborhoods.
- Historic-property lots. South Pasadena and Pasadena historic-property rules cap ADUs at 1 story and 16 ft. The Wilshire’s single-story design fits the envelope without compromise.
- High Risk Fire Areas. Cities like South Pasadena require detached ADUs to sit within 150 ft of the front property line. A small footprint makes that placement easier on most lot geometries.
- Multigenerational housing. A studio works well for an aging parent, an adult child, or a long-term guest who values privacy without needing a full second-bedroom layout.
- Pure rental investment. The lower upfront cost ($219K vs. $329K-$459K for larger Signature Homes) shortens the payback period to 5-8 years on most LA rental markets.
Renting your studio ADU
A well-built studio ADU in Los Angeles rents for $1,800-$2,500 per month depending on location and finish level. Premium markets like Beverly Hills, Santa Monica, Westwood, and Pasadena push the upper end ($2,200-$3,000+). Valley markets and smaller adjacent cities sit in the lower-middle range ($1,800-$2,200).
Payback math at the Wilshire’s $219,000 fixed price:
- $2,000/mo rental income = $24,000/year. Simple payback in 9.1 years.
- $2,500/mo rental income = $30,000/year. Simple payback in 7.3 years.
- $3,000/mo rental income (Westside premium) = $36,000/year. Simple payback in 6.1 years.
Plus the appraisal lift — Los Angeles appraisers now value permitted ADUs as income-producing units, not as accessory structures. A well-built Wilshire typically adds $200K-$300K to the property's appraised value, which on top of the rental income turns the project into a genuine financial asset, not a sunk cost.
Run the math for your specific lot and rental market with our ROI Calculator.
Studio ADU vs. 1-bedroom — which is right for your lot?
Studio (Wilshire) vs. 1-bedroom (Sunset or Westwood) is the most common decision homeowners face when sizing their ADU. The tradeoff is clear:
| Wilshire (Studio) | Sunset (1BR) | Westwood (1BR) | |
|---|---|---|---|
| Size | 400 sqft | 480 sqft | 550 sqft |
| Fixed price | $219,000 | $239,000 | $259,000 |
| Impact fees | $0 (exempt) | $0 (exempt) | $0 (exempt) |
| Typical LA rent | $1,800-$2,500 | $2,300-$3,000 | $2,500-$3,200 |
| Payback (mid-rent) | ~7-9 years | ~7-9 years | ~8-10 years |
| Best for | Single occupant, tightest lots, fastest ROI | Couples, longer-term tenants, slightly higher rent | Compact families, family suites, premium 1BR rents |
All three stay under the 750 sqft impact-fee exemption. All three fit on most single-family lots with the standard 4-ft side and rear setbacks. The decision is mostly about your tenant target and your lot’s specific geometry.
Studio ADU questions, answered
The questions homeowners actually ask before they build a studio ADU — with citations to California state law where applicable.
What is the smallest ADU I can build in California?
The state-law minimum for a permitted ADU is 150 square feet — the threshold for an “efficiency unit” under California Health and Safety Code § 17958.1. Most cities also enforce this floor in their local ordinance.
In practice, the smallest practical studio ADU is 350-400 square feet — enough for a queen bed, a kitchenette, a full bathroom, and a small living area. CALI ADU’s Wilshire Signature Home is 400 sqft, the most efficient size that still rents at market rate.
How much does a studio ADU cost in Los Angeles?
Custom-designed studio ADUs in LA typically cost $300-$500 per square foot when you add up architecture, engineering, permitting, construction, and finishes — putting a 400-500 sqft studio in the $120K-$250K range. CALI ADU’s Wilshire Signature Home is fixed-price at $219,000 all-inclusive: design, engineering, permits, construction, interior finishes, appliances, and utility connections.
Are studio ADUs eligible for the impact-fee exemption?
Yes. California Gov. Code § 66318 exempts every ADU under 750 square feet from impact fees. A 400 sqft studio sits well below the threshold — $0 in impact fees regardless of the city’s standard ADU impact-fee schedule.
On a 1,200 sqft 3-bedroom ADU, impact fees can run $10,000-$30,000+ depending on the city. On a studio: zero. This is one of the strongest reasons studio ADUs pencil on rental income.
What’s the floor plan of a studio ADU?
A well-designed studio ADU uses an open floor plan: the kitchen, dining, sleeping, and living areas occupy a single connected space, with the bathroom as the only enclosed room. The Wilshire’s 400 sqft layout includes a sleeping alcove (separated from the main living area by a partial wall or built-in cabinetry), an open living and kitchen space, a full bathroom, and a private entrance. Ceiling height of 9-10 feet keeps the space feeling generous despite the compact footprint.
Can I rent a studio ADU on Airbnb?
It depends on your city. California state law (Gov. Code § 66314(e)) allows ADU rentals of 30 days or longer. Some cities — Burbank, South Pasadena, Pasadena, Beverly Hills — match the 30-day floor. Others tighten further: Burbank requires 90+ days, Beverly Hills's Incentive ADU requires 1+ year. Most LA-area cities do not permit short-term (under 30 days) rentals on ADUs of any size, including studios. For practical purposes, treat your studio ADU as a long-term rental asset.
How long does it take to build a studio ADU?
From contract signing to certificate of occupancy: 6 to 8 months for a CALI ADU Wilshire Signature Home. That breaks down roughly as 2-3 months of plan check and permitting at your city’s building department, then 4-5 months of on-site construction.
Studio ADUs build faster than larger units because the foundation, framing, electrical, and finish scopes are all smaller. We guarantee the timeline in writing — if we miss it, we pay you a daily delay penalty until we hand you the keys.
Studio ADU vs. 1-bedroom ADU — which should I build?
Studio (400 sqft, Wilshire, $219K) makes sense when rental yield is the primary goal (lower build cost = faster ROI), the lot is tight (minimum footprint preserves yard), or the unit is for a single occupant (extended family, home office, guest suite).
1-bedroom (480-550 sqft, Sunset or Westwood, $239K-$259K) makes sense when you need a separate sleeping room (better for couples, longer-term tenants), the lot easily accommodates the larger footprint, or you want to rent at the higher 1-BR rate (typically $400-$700/mo more than a studio). Both stay under the 750 sqft impact-fee exemption.
Ready to build your
studio ADU?
We’ll check your lot, walk you through the Wilshire’s 400 sqft footprint, and give you a fixed number — before you commit to anything. 15 minutes.
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