Custom modern ADU plans. Architect-designed for your lot.
Most modern ADUs in California come from prefab catalogs — standardized boxes, single-story only, take it or leave it. We design custom modern ADUs for clients who want something specific to their lot, site, and architectural taste. Plans + permits fixed-price; construction quoted separately.
Custom modern ADU plans we’ve designed
Architect-designed modern ADUs from CALI ADU’s portfolio of custom projects. Each plan was designed for a specific lot and client. Available as a fixed-price plans + permits package; construction quoted separately.
Awaiting upload — drop renders into /images/categories/modern/
Custom Modern ADU — Architect-Designed for Your Lot
Bespoke modern ADU plan tailored to a specific lot, orientation, and client preferences. Pre-engineered for ministerial ADU permitting under California state law. Floor plan and renderings coming.
Plans + Permits: Fixed price — quoted on request · Get pricing →
Modern Flat-Roof Single-Story
Compact modern with clean horizontal lines and a flat roof. Best for tight lots and Westside coastal-modern aesthetic.
Modern Two-Story Townhouse Style
Two-story modern with full second-floor primary suite. Designed for footprint-efficient builds on tight residential lots.
Modern Hillside / Cantilever
Modern ADU embedded into hillside terrain. Cantilevered floor plate with floor-to-ceiling glazing toward the view.
Modern Courtyard Plan
L-shaped or U-shaped modern ADU around a private courtyard. Indoor-outdoor integration with sliding glass.
What’s Included
Custom architectural design, structural engineering, Title 24 compliance, and ministerial permit processing. One fixed quote.
Want a Turnkey Modern ADU?
Our Signature Home lineup includes modern style variants on every model — design + permits + construction in one fixed price. See the full lineup.
Need pricing on a custom modern ADU plan for your specific lot? Request a quote →
On this page
What is a modern ADU?
“Modern” in residential architecture refers to a set of design choices that emerged from the Mid-Century Modern movement and evolved through the contemporary architecture of the 2000s and 2010s. For ADUs specifically, modern means:
- Clean horizontal lines — long, low rooflines and minimal vertical ornament.
- Flat or low-slope roofs — flat-roof variants (sometimes with a small parapet) or pitched roofs at very shallow angles.
- Large glazing — floor-to-ceiling windows on at least one elevation, often facing the rear yard for privacy.
- Indoor-outdoor integration — sliding glass doors connecting living space to outdoor patios or decks.
- Minimal exterior ornament — no decorative trim, brackets, or shutters. Material and form do the work.
- Contemporary materials — smooth stucco, fiber cement panels, standing-seam metal roofing, board-form concrete accents.
Traditional ADUs lean Craftsman, Spanish Colonial Revival, or other period styles with pitched roofs, exposed rafter tails, decorative trim, and natural materials. The same CALI ADU Signature Home floor plan often comes in BOTH styles — the Sunset, Melrose, and Wilshire each have modern flat-roof variants AND traditional gable variants. The choice is aesthetic, not structural.
How the custom modern plans offer works
The custom modern offer is structurally different from our Signature Home lineup. With Signature Homes, we sell a complete turnkey package — design, permits, AND construction at one fixed price. With custom modern plans, we sell two of those three:
- Custom design — fixed price. Architect-designed plans tailored to your lot, orientation, neighborhood context, and aesthetic. Same plan-quality standard as our productized Signature Homes.
- Permit processing — fixed price. We handle the city submittal, plan check corrections, and ministerial approval coordination through to issued building permit. State law requires the city to approve or deny within 60 days of a complete application (Gov. Code § 66317).
- Construction — quoted separately. You hire your own general contractor (or one we recommend), and they price construction based on your specific lot conditions, finish selections, and site complexity.
The model fits homeowners and developers who want bespoke modern design without the rigidity of a productized line:
- Homeowners who want a modern ADU that responds to their specific lot, view orientation, or design intent.
- Architects and designers looking for a plan-and-permit foundation they can customize for specific clients.
- Developers and builders who already have construction crews and want pre-engineered modern plans they can permit and build.
For a fully turnkey project (one fixed price including construction), our Signature Home lineup includes modern style variants on every model — covered in the next section as a secondary alternative.
Signature Home modern variants — the turnkey alternative
For homeowners who prefer turnkey over custom design, every model in our 9-Signature-Home lineup is available in modern style variants — same fixed-price all-inclusive package (design + permits + construction in one quote). No custom design timeline; faster path to a permitted, built ADU.
The standout in the Signature Home modern lineup is the two-story trio — Fairfax, Venice, and Culver — designed for the 22-25 ft height envelopes that most LA-area cities apply to detached ADUs. CALI ADU is the only company in LA offering true two-story modern ADUs at a fixed price (prefab transport constraints make this impossible for factory-built units).
- The Fairfax — 2 BR / 1.5 BA, 840 sqft, $339,000. Entry-level two-story Signature Home. Flat-roof variant fits 22 ft caps; gable variant fits 25 ft.
- The Venice — 2 BR / 2 BA, 1,080 sqft, $399,000. Mid-tier two-story with full second-floor primary suite. Same roof variants.
- The Culver — 3 BR / 2.5 BA, 1,200 sqft, $459,000. Flagship two-story with three bedrooms across two levels. Same roof variants.
All three fit on a 20′ × 30′ footprint or smaller — meaning a two-story unit takes the same yard space as a single-story 600 sqft ADU but delivers 800-1,200 sqft of living area. On Westside, Beverly Hills, South Pasadena, and other tight-lot markets, that footprint efficiency is the entire reason to go two-story.
City-by-city height fit:
| City / Zone | Detached ADU height cap | Fits with this variant |
|---|---|---|
| Beverly Hills, Central Area south of Santa Monica Blvd | 22 ft | Flat-roof variant |
| Beverly Hills, Central Area north of Santa Monica Blvd | 25 ft | Gable variant |
| South Pasadena (non-historic, non-HRFA) | 22 ft pitched | Gable variant |
| Santa Monica | 24 ft (2-story by right) | Either variant |
| Culver City | 27 ft flat / 30 ft pitched | Either variant, easy fit |
| Los Angeles (most zones) | 28-45 ft | Either variant, easy fit |
The two-story modern Signature Home trio
Fairfax, Venice, Culver — the three two-story Signature Homes. Each available in flat-roof modern and gable variants to fit the height cap on every LA-area city's ADU ordinance.
The Fairfax
2 BR / 1.5 BA · 840 sqft · 2-story
$339,000 all-inclusive iFixed contract price for the Signature Home on a standard lot. Site-specific work — soil reports, utility routing, driveway, retaining walls — is identified and priced upfront, before you sign.
See model →
The Venice
2 BR / 2 BA · 1080 sqft · 2-story
$399,000 all-inclusive iFixed contract price for the Signature Home on a standard lot. Site-specific work — soil reports, utility routing, driveway, retaining walls — is identified and priced upfront, before you sign.
See model →
The Culver
3 BR / 2.5 BA · 1200 sqft · 2-story
$459,000 all-inclusive iFixed contract price for the Signature Home on a standard lot. Site-specific work — soil reports, utility routing, driveway, retaining walls — is identified and priced upfront, before you sign.
See model →Modern style variants across the single-story lineup
The two-story trio is the differentiator, but every single-story Signature Home also comes in modern variants. The full modern options across the 6 single-story models:
- Wilshire (400 sqft Studio): stucco gable, modern farmhouse exterior, warm horizontal siding.
- Sunset (480 sqft 1BR): modern flat-roof, Spanish flat-roof, modern farmhouse.
- Westwood (550 sqft 1BR): standard exterior, modern farmhouse, side-view variants.
- Laurel Canyon (660 sqft 2BR): modern flat-roof Spanish, modern flat-roof contemporary.
- Melrose (800 sqft 2BR/2BA): modern flat-roof, Spanish flat-roof, modern farmhouse.
- Lincoln (1,000 sqft 3BR/2BA): modern variant available on request.
Every variant is the same fixed price as the standard model. The roof profile, cladding, and trim package change — the floor plan, dimensions, structural envelope, and pricing stay the same.
Why prefab competitors can’t match this
Prefab modern ADUs (the well-known national brands you’ve seen advertised) are built in a factory and trucked to the lot on a flatbed. The model is genuinely innovative for some single-story scenarios — quality control is high, schedules are predictable, and the factory-line economics keep pricing competitive.
But there are three structural limits no prefab company has solved:
- Single-story only. Standard truck-and-trailer dimensions cap the unit at single-story. A two-story prefab exceeds bridge clearance, requires oversized-load permits in every county it traverses, and triggers escort-vehicle requirements that price the project out of the business model.
- Site work and finishing not included. The prefab unit arrives at the lot and a separate contractor handles foundation pour, utility hookups, finishes, exterior connections, and inspection. The homeowner manages that contractor relationship and the cost overrun risk.
- Limited customization. The factory line economics depend on standardized cuts, pre-made cabinetry, and a small set of finish options. Real customization breaks the model and adds custom-build cost on top of prefab cost.
CALI ADU builds on-site. Removes the transport cap entirely. Includes site work, foundation, utility connections, finishes, and inspection in the fixed-price contract. And the architect-designed Signature Homes are built for site-specific California permitting, not factory-line standardization.
Floor plans + sizes
The full modern Signature Home lineup, sized from studio to 1,200 sqft three-bedroom two-story:
| Model | Configuration | Size | Stories | Fixed price |
|---|---|---|---|---|
| The Wilshire | Studio / 1 BA | 400 sqft | 1 | $219KiFixed contract price for the Signature Home on a standard lot. Site-specific work — soil reports, utility routing, driveway, retaining walls — is identified and priced upfront, before you sign. |
| The Sunset | 1 BR / 1 BA | 480 sqft | 1 | $239KiFixed contract price for the Signature Home on a standard lot. Site-specific work — soil reports, utility routing, driveway, retaining walls — is identified and priced upfront, before you sign. |
| The Westwood | 1 BR / 1 BA | 550 sqft | 1 | $259KiFixed contract price for the Signature Home on a standard lot. Site-specific work — soil reports, utility routing, driveway, retaining walls — is identified and priced upfront, before you sign. |
| The Laurel Canyon | 2 BR / 1 BA | 660 sqft | 1 | $289KiFixed contract price for the Signature Home on a standard lot. Site-specific work — soil reports, utility routing, driveway, retaining walls — is identified and priced upfront, before you sign. |
| The Melrose | 2 BR / 2 BA | 800 sqft | 1 | $329KiFixed contract price for the Signature Home on a standard lot. Site-specific work — soil reports, utility routing, driveway, retaining walls — is identified and priced upfront, before you sign. |
| The Fairfax | 2 BR / 1.5 BA | 840 sqft | 2 | $339KiFixed contract price for the Signature Home on a standard lot. Site-specific work — soil reports, utility routing, driveway, retaining walls — is identified and priced upfront, before you sign. |
| The Lincoln | 3 BR / 2 BA | 1,000 sqft | 1 | $389KiFixed contract price for the Signature Home on a standard lot. Site-specific work — soil reports, utility routing, driveway, retaining walls — is identified and priced upfront, before you sign. |
| The Venice | 2 BR / 2 BA | 1,080 sqft | 2 | $399KiFixed contract price for the Signature Home on a standard lot. Site-specific work — soil reports, utility routing, driveway, retaining walls — is identified and priced upfront, before you sign. |
| The Culver | 3 BR / 2.5 BA | 1,200 sqft | 2 | $459KiFixed contract price for the Signature Home on a standard lot. Site-specific work — soil reports, utility routing, driveway, retaining walls — is identified and priced upfront, before you sign. |
Every model is available in modern style variants. See each model page for the full floor plan, exterior renderings of all available variants, and 3D walkthrough.
Pricing custom modern plans + permits
The custom modern plans + permits offer is priced as a fixed-quote package per project, not as a per-square-foot or per-unit variable. The plan we design for you determines the price; permit processing is included in the same quote.
What’s included in the fixed quote:
- Custom architectural design tailored to your lot, orientation, and aesthetic preferences
- Structural engineering for the modern configuration
- Title 24 energy compliance documentation
- Site-specific design (lot dimensions, setbacks, utility connections, view orientation)
- Complete permit-submittal package for your city’s building department
- Plan-check correspondence and corrections through to issued permit
What’s NOT included — quoted separately by you or your contractor:
- Construction labor and materials
- Site grading, foundation, and demolition
- Utility connection work (water, power, electric, gas)
- Interior finishes, fixtures, and appliances
- Landscape and exterior site work
For a current custom modern plans pricing quote on your specific lot, start a Backyard Review — we walk through the lot conditions, design intent, and budget, then provide a fixed plans + permits quote within a few business days.
For comparison: our turnkey Signature Home lineup with modern variants prices from $219,000 (Wilshire studio) to $459,000 (Culver 3BR/2.5BA two-story) all-inclusive — design, permits, AND construction in one quote.
Where a modern ADU fits best
Modern ADU style is broadly appropriate across LA County, but a few markets are particularly strong fits:
- Westside neighborhoods. Mar Vista, Venice, Culver City, West LA, Cheviot Hills — modern style is the dominant residential aesthetic on a meaningful share of the housing stock. A modern ADU reads as appropriate, even welcomed.
- Hillside lots. Modern style’s clean horizontal lines work especially well on hillside terrain where the unit must be embedded into the slope.
- Tight-lot two-story builds. The Fairfax/Venice/Culver two-story trio is the strongest case for modern — the small footprint with full vertical living suits Westside lot constraints exactly.
- Investment / rental focus. Modern aesthetic photographs well, rents at the upper end of the local market, and signals quality construction to prospective tenants.
- Multifamily developer projects. When the modern ADU is one of multiple new units on a multifamily lot, design coherence with the existing building matters — modern Signature Homes are often the best match for mid-century or contemporary multifamily.
Modern ADU questions, answered
The questions homeowners ask before they pick modern over traditional, and how CALI ADU’s lineup compares to prefab and custom alternatives.
What makes an ADU “modern” vs. traditional?
Modern ADUs are characterized by clean horizontal lines, flat or low-slope roof profiles, large glazing, integration of indoor and outdoor space, minimal exterior ornament, and contemporary materials (smooth stucco, fiber cement panels, standing-seam metal roofing).
Traditional ADUs lean Craftsman, Spanish Colonial Revival, or other period styles with pitched roofs, exposed rafter tails, decorative trim, and natural materials. The same Signature Home floor plan often offers both — the Sunset, Melrose, and Wilshire each come in modern flat-roof and traditional gable variants.
Can I get a two-story modern ADU in LA?
Yes — and CALI ADU is the only company in LA offering true two-story modern ADUs at a fixed price. Three Signature Homes:
- Fairfax — 2BR/1.5BA, 840 sqft, $339K
- Venice — 2BR/2BA, 1,080 sqft, $399K
- Culver — 3BR/2.5BA, 1,200 sqft, $459K
All three available in flat-roof and gable-roof variants. Each fits the 22-25 ft height caps that most LA-area cities apply to detached ADUs (Beverly Hills 22 ft south / 25 ft north, South Pasadena 22 ft pitched, etc.) with the right roof choice.
How much do custom modern ADU plans cost?
The custom modern plans + permits offer is priced as a fixed quote per project. The price depends on the complexity of the design, lot conditions, and the city permitting environment — quoted on request after a Backyard Review.
For comparison: the turnkey Signature Home modern variants are fixed-price from $219,000 (Wilshire studio with stucco-gable) to $459,000 (Culver 3BR/2.5BA two-story with flat-roof). Those prices include construction; the custom modern plans + permits price does not.
Why isn’t construction included in the custom modern plans price?
Two reasons. First, the custom modern offer is structurally different from our Signature Home lineup. Signature Homes are productized end-to-end — same plans, same construction sequence, same fixed price every time. Custom modern plans are construction-customizable: lot conditions vary more, finish selections vary more, and the construction scope is too site-specific for a single fixed price.
Second, the custom modern audience often includes architects, designers, and developers who already have construction relationships and don’t need (or want) the construction layer bundled in. The plans + permits offer fits that audience cleanly. We’re happy to recommend a contractor for homeowners who don’t already have one.
Why do most modern ADU companies only offer single-story?
Transport constraints. Prefabricated ADUs are built in a factory and trucked to the lot on a flatbed. Standard truck-and-trailer dimensions cap the unit at single-story — anything taller exceeds bridge clearance, requires permits for oversized loads, and triggers escort-vehicle requirements that price the project out of the prefab business model.
CALI ADU builds on-site, which removes the transport cap entirely. Two-story is just a design choice, not a logistics impossibility.
How is CALI ADU different from prefab modern ADU companies?
Three structural differences:
- Architecture: CALI ADU’s plans are architect-designed for site-specific permitting in California, not factory-built standardized boxes.
- Two-story availability: CALI ADU has the only fixed-price two-story modern ADU lineup in LA — prefab transport constraints make this impossible for factory-built units.
- Construction execution: CALI ADU’s contract includes construction with a guaranteed completion timeline; prefab companies typically deliver the unit and leave site work, foundation, utility connections, and finishing to the homeowner’s separate contractor.
The result: one fixed price covers the whole project.
What modern style variants are available?
Across the 9-Signature-Home lineup, modern variants include:
- Sunset modern flat-roof, Sunset Spanish flat-roof
- Melrose modern flat-roof, Melrose Spanish flat-roof
- Wilshire stucco gable, Wilshire modern farmhouse
- Westwood modern farmhouse, Westwood standard exterior
- Two-story trio (Fairfax, Venice, Culver) flat-roof modern variants
Each variant changes the roof profile, exterior cladding, and trim while keeping the same floor plan and pricing.
Where can I see a modern ADU built by CALI ADU?
Browse the 126-project portfolio at /adu-portfolio/. Recent modern ADU projects include two-story builds in West Adams, modern flat-roof designs in Westside neighborhoods, and contemporary garage conversions. Each project page shows the completed home, floor plan, and project details.
The Backyard Review can also include site visits to recent CALI ADU modern ADU projects in your specific neighborhood.
Ready to build your
modern ADU?
We’ll check your lot, walk you through the height cap and which roof variant fits, and give you a fixed number — before you commit to anything. 15 minutes.
15 minutes · No obligation