If there’s one thing we’ve learned this year, it’s that accessory dwelling units (ADUs) aren’t going anywhere. In fact, they’re chugging along at full force as new regulations make their mark, homeowners are letting their creativity bloom, and designers are pushing the limits of what’s possible in small-space living.
And now, we’re handing out flowers to the 10 best ADUs to earn their keys in 2025.
Every year, Maxable’s Best ADU of the Year Competition celebrates the most impressive projects from across California and the rest of the US. ADUs that don’t just look great, but solve real challenges of space, budget, and lifestyle.
And YOU have the opportunity to vote for your favorite and crown the winner.
Let’s take a look at our finalists below, and vote for your favorites here: https://maxablespace.com/best-adu-submissions/
Chamomile Cottage, Arlington, MA
Modular Design and Build: Backyard ADUs
Size: 567 sq ft, 1 bed, 1 bath
If a cozy cup of tea was an ADU, we think it’d look like this!
Designed to bring an aging father closer to his family and young grandchildren, this modular build balances warmth, accessibility, and beautiful design. As one of the first detached ADUs completed under Massachusetts’ new ADU law, it also marks a milestone for backyard living in the state.
Built with collaboration between Backyard ADUs and a homeowner with impeccable design taste, the result is both functional and heartfelt. Chevron wood flooring, warm olive walls, and a charming fireplace make the space feel like home from the moment you step inside. Skylights fill the rooms with natural light, while the ADA-compliant bathroom ensures comfort and safety for years to come.
Alora ADU, San Diego, CA
Designer: Ruland Design Group
Builder: Glann Fick, Coastline Construction
Size: 1,000 sq ft, 2 bed, 2 bath duplex
This project is a beautiful example of how ADUs can bring generations together while adding long-term value to a property. The homeowners created not one, but two attached backyard homes. One was designed for an aging mother, and the other for rental income to support the family. Together, the units make space for four generations to stay close while still maintaining privacy and independence.
Both ADUs were designed with light, openness, and connection to the outdoors in mind. High ceilings and clerestory windows fill the interiors with natural light, while large sliding glass doors open to private patios for easy indoor-outdoor living. Each space feels modern and welcoming, complete with well-appointed kitchens and roomy islands perfect for family meals or morning coffee.
It’s a true example of multigenerational living done right.
Copperline ADU, San Diego, CA
Designer and Builder: SnapADU
Size: 980 sq ft, 2 bed, 2 bath
This Spanish-style ADU in Rancho Santa Fe was designed to blend seamlessly with the community’s strict architectural standards. The homeowner, a roofing contractor, personally installed the boosted tile roof to match the main home, turning HOA requirements into an opportunity to create a timeless retreat. Today, the ADU serves as a private space for family and guests.
Every element, from hand-textured stucco to arched porch openings and copper gutters, was carefully chosen to mirror the primary residence. Inside, faux wood ceiling beams add warmth to the great room, while custom shelving and professional-grade appliances enhance the kitchen. Each bedroom features an ensuite bath and walk-in closet, with a back entrance leading to a mudroom and laundry area.
Brick House ADU, Denver, CO
Designer and Builder: ADU4U
Size: 938 sq ft, 1 bed, 1.5 bath
This ADU project breathes new life into an old, historic building, while preserving its authentic character and respecting its roots. Building a modern structure within an 138 year old structure was an innovative solution to achieve this.
In historic Curtis Park, Denver’s oldest neighborhood, an 1886 brick carriage house stands as a testament to the passage of time. The building sits inside the boundaries of Denver’s historic Curtis Park, so all exterior design and material selections had to be approved through the city’s Landmark Commission.
ADU4U turned this once-unlivable structure into a cozy, modern home while preserving its historic charm. To bring it up to today’s safety standards, the team strengthened the old brick with a new steel frame and carefully reused original materials throughout the interior. The hayloft door became the powder room door, and the old floor joists were turned into a beautiful kitchen peninsula.
Now, this light-filled ADU perfectly balances historic character with modern comfort. It’s truly a shining example of how old buildings can be reimagined for today’s living.
Longview ADU, Washington D.C.
Designer: Ileana Schinder
Builder: J Cabido Designs
This project is a creative transformation of an abandoned garage and storage space into a bright and efficient one-bedroom ADU. By keeping the original structure’s footprint, the design team minimized both construction costs and the visual impact on the surrounding property.
Every detail was planned with sustainability in mind. From upgraded insulation to energy-efficient mini splits and an energy recovery ventilator, the ADU meets Washington DC’s strict environmental standards while maintaining year-round comfort.
Restoring the building’s existing openings allowed natural light to flood the interior, creating a warm and inviting space that feels much larger than its footprint. The result is a thoughtful blend of preservation, sustainability, and smart design, breathing new life into what was once an overlooked structure.
Sagebrush ADU, Menlo Park, CA
Designer: Inspired ADUs
Builder: Integrum Construction
This ADU is a masterclass in craftsmanship and timeless design. Every detail, from the cedar shake siding to the copper flashings, was carefully chosen to mirror the main home and create a seamless, cohesive look. Instead of competing with the original architecture, it enhances it, feeling like it has always been part of the property.
Natural materials play a starring role here. The cedar and copper will continue to age beautifully, adding warmth and character over time. Inside, handmade tile, custom cabinetry, and a cozy loft make the space feel elevated yet inviting. Every inch was designed with intention, balancing function, beauty, and authenticity.
This ADU proves that small-scale construction can be both refined and enduring.
Ashby ADU, Piedmont, CA
Designer: Tuan Le Design
Builder: Atelier19AD6
Size: 800 sq ft, 2 bed, 1 bath
Built on a steep slope, the project faced challenges with utility coordination, subcontractors, supply chain delays, and neighbor considerations, yet the team navigated every obstacle to deliver a standout result.
The unit is fully electric, with a heat pump, water heater, and solar panels, making it efficient and environmentally conscious. Skylights and floor-to-ceiling four-panel sliding glass doors fill the interior with natural light, creating a bright, airy atmosphere.
The modern design continues on the exterior with sleek wood paneling that complements the contemporary interior. The result is a stylish, functional ADU that maximizes both the views and the livable space
Brushstroke ADU, Newcastle, CA
Designer and Builder: A+ Construction ADU Builders
Size: 1,198 sq ft + 800 sq ft deck, 3 bed, 2 baths
Our client didn’t want to separate three generations of their family, so they built a second home in their backyard. This ADU allows their parents to live independently with their own routines and art studio, while staying just steps from family dinners, grandkid hugs, and everyday life together.
At 1,200 sq. ft., the ADU includes three bedrooms, two bathrooms, and a large open living area. The layout prioritizes comfort, easy movement, and aging-in-place, with wide circulation paths, direct deck access from the primary bedroom, and plenty of natural light. A dedicated art studio with custom cabinetry and large windows supports the grandmother’s creative routine. The best feature? An 800 sq. ft. covered deck and carefully chosen exterior finishes. All of these details make the ADU feel integrated with the main home, creating a thoughtful, functional, and long-term living space for the whole family.
Alcove ADU, Los Angeles, CA
Designer: Homeowner
Builder: Doobek Brothers
Size: 593 sq ft, 1 bed, 1 bath
What started as a retrofit for a carport turned into a fully functional ADU, making smart use of limited space while navigating strict city codes. Because the property sits on a hillside, any addition beyond the existing roofline would have required expensive drainage to the street, so the design works entirely within the original footprint.
The interior feels calm and spacious thanks to thoughtful layout, finishes, and furniture. A double wall between the kitchen and bathroom cleverly hides appliances while providing storage for cleaning supplies, making the space feel open and uncluttered. Temperature and sound insulation reduce energy costs for both units, making it highly efficient. Windows were sized to align with the upstairs unit, creating visual harmony. With parking right outside and a potential deck planned for the upper unit, this ADU demonstrates how careful design can turn code restrictions into a livable home.
Elevare ADU, San Diego, CA
Designer: Sergio Perlata
Builder: HM Construction
Size: 479 sq ft, 1 bed, 1 bath
This daring ADU was built on top of the homeowner’s existing house to preserve the garage while creating a luxurious, functional space. What started as a bold idea and labor of love resulted in a retreat that balances comfort, style, and modern California living.
The design maximizes natural light, features high-end finishes, and offers seamless indoor-outdoor flow. Privacy for the main house was carefully considered, and practical choices like spa-like micro-cement in the bathroom create a durable, low-maintenance, and rental-friendly space.
More than just a guest house, this ADU is a thoughtfully crafted space that inspires relaxation and connection.
Now it’s your turn to cast your vote and crown the winner.
