Accessory Dwelling Unit Design in California: Affordable Quality Architecture

A bright kitchen with wooden cabinets, a white marble countertop, a window with a view of a backyard, a stovetop, a bowl of apples, a flower arrangement, and a patio outside.
Bright, airy kitchen with skylights, light wood cabinets, a central island, a chandelier, sliding glass doors, and a sitting area with a sofa and glass coffee table.

JH2 Architects specializes in accessory dwelling unit design throughout Southern California, creating affordable, high-quality ADUs for multigenerational living, rental income, and guest accommodations.

Our approach balances cost efficiency with thoughtful architecture. With simple, well-designed structures that maximize space while matching your main home's aesthetic. Whether you're considering a modern ADU, a traditional guest house, a California ranch style, or a coastal cottage, we offer architectural programs tailored to your site, budget, and lifestyle needs.

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Waco ADU

San Diego, California

Completed 2018

1,200 sf

3 Bedrooms, 2 Bathrooms, Kitchen, & Living Room

Maximized bedroom count (3 bedrooms) per homeowner’s request. Simple affordable design with best efficient modular system 25’ x 49’. Easy to construct as simple Architectural/Structural well designed, open kitchen living space layout.

Living room with large windows, a gray sofa, a white cushioned loveseat, a small wooden coffee table with a potted plant, a chandelier, a TV, and plants in pots.
Floor plan and 3D rendering of a 1,200 square foot, three-bedroom house with an open kitchen, living room, and outdoor yard, showing interior layout and room design.

Detached ADU in the back yard. Access from alley road. ADU located in 2nd Floor in accessory building since it is in hillside site. Efficient tight 2 bedrooms with kitchen living room area for ocean view. ADU proposed to match with main modern architectural style. Simple affordable design.

San Diego, California

In Progress

700 sf

Coronado ADU

2 Bedrooms, 1 Bathroom, Kitchen, Living & Dining Room

Architectural rendering of two modern white houses on a hillside, labeled 'main house' and 'ADU', with balconies, stairs, and greenery.

Canterbury ADU

San Marino, California

In Progress

990 sf

2 Bedrooms, 1 Bathroom, Kitchen, Living & Dining Room

Maximized bedroom count (3 bedrooms) per homeowner’s request. Simple affordable design with best efficient modular system 25’ x 49’. Easy to construct as simple Architectural/Structural well designed, open kitchen living space layout.

Architectural blueprint drawing of a single-story house showing four elevation views: left, front, right, and rear. The house has a gabled roof with dark shingles, white exterior walls, various windows, a front door, a garage with a wooden door, and landscaped surroundings with trees.
Site plan of a property showing a main building, ADU (Accessory Dwelling Unit), a pool, landscaping, fencing, driveway, and various other features outlined and labeled with measurements.

Guest House ADU

California

In Progress

990 sf

Architectural rendering of a modern residential outdoor space with a small pool, wooden deck, and outdoor seating areas, surrounded by multi-story buildings with large windows and balconies.


Separate guest house for perfect hosting.

1 Bedroom, 1 Bathroom, Kitchen, Entertainment Room

Rendering of a modern, multi-story house with wooden accents, large glass windows, and rooftop terraces with outdoor furniture and a small pool at the backyard.
Digital rendering of a modern two-story house with a pool, outdoor seating, and outdoor staircase against a cloudy sky.
Architectural rendering of a modern residential outdoor area with a small pool, wooden deck, stone and white exterior walls, and slatted wooden privacy screens.

ADU Project Lists in California

Located in San Diego, Los Angeles & Orange County

Waco ADU: 1,160 SF, 3 Beds, San Diego

Van Nuys ADU: 1,000 SF, 2 Beds, Van Nuys

Canterbury ADU: 986 SF, 2 Beds, San Marino

Genessee ADU: 1,046 SF, 1 Bed, Los Angeles

Coronado ADU: 688 SF, 2 Beds, San Diego