7 Smart ADUs and Additions That Cost as Little as $18K

From a shingled studio in Minneapolis to a two-bedroom guesthouse in L.A., these backyard projects are something to emulate.
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Whether you’re in need of a guesthouse, art studio, home office, yoga practice space—or all of the above—a home addition or backyard ADU can do the trick. These multifunctional spaces open up new possibilities in lifestyles and living arrangements, and don’t necessarily have to break the bank. Ranging from $18,275 to $248,658, the clever projects below break down the costs of carving out some additional room.

A Creative Couple in Minneapolis Build a Multipurpose Backyard Studio for $18K 

This 195-square-foot, shingled studio includes a library, reading nook, and workstation—and it’s totally DIY. Creative couple Michael and Christina Hara built the retreat just steps away from their back door, in order to carve out "space for creativity and respite from our chaotic, toddler-filled house," as Michael explains. The project, called the Fish Scale Studio, took eight months to complete, with Haras doing all of the design and construction themselves—for just $18,275.  

The couple finished the exterior siding with deep purple shingles made of Hardie board. "We wanted an exterior cladding that was durable, low-maintenance, and relatively DIY-friendly," says Michael. "When looking at our options at the local hardware store, the fish-scale shape popped because it was unique, quirky, and not super serious—and yet could create a contemporary look through uniformly using it with woven corners and minimal detailing."

The studio is a multipurpose destination for the hardworking pair (he’s an architect and product designer; she’s a fashion designer). Almost everything—from exterior lighting and interior furnishings, to the turntable and speakers—was designed and built by the creative couple.

According to Michael, the centralized table is a contemporary take on a traditional trestle table, combining raw steel plate "legs" with a bleached ash slab with wenge keys. The chairs are powder-coated steel and maple, with sheepskin cushions, and the floors are whitewashed birch hardwood. The chandelier is inspired in part by a Lindsey Adelman design and built to fit the space.

A Moldy Shed Becomes a Lively Backyard Hangout for Less Than $40K

Once a dilapidated garage, this flexible garden studio in Seattle now serves as an all-weather hub for Ella Dillon, and her 10-year-old daughter, Isabelle. After moving into the Craftsman-style home in Seattle’s Ballard neighborhood in 2006, Ella was ready to expand into the garden studio—envisioning it as a place for Isabelle to do arts and crafts, for friends and family to gather—and as additional storage for games, gardening tools, and exercise equipment. 

The original run-down shed wasn’t very functional: The roof leaked, the carpet had sprouted mold, and the narrow quarters were sectioned off as two parking spots and two office spaces. So Ella engaged Mutuus Studio to help figure out an optimal design for the 360-square-foot shed—one that would encompass garden shed, exercise room, office, playroom, and outdoor dining space all while staying within a modest budget.

The simplicity of Ballard Garden Studio makes the space feel larger than its 360 square feet, and allows it be versatile for a variety of uses.

Isabelle's hideaway is tucked within the back wall and includes one of the original windows. While covering a window is not a traditional design move, it added natural light to the small space and gives it a tree house-like feel.

A Portland Couple Design and Build a Compact Home For $222K

A Portland, Oregon, couple Scott Mooney and Lauren Shumaker built this  sustainable, two-bedroom, 624-square-foot ADU for $221,580. Spurred by the city’s generous accessory dwelling unit (ADU) incentives and a desire to reduce their environmental footprint, the couple—he is an architect and she is a construction engineer—designed and built the elegant backyard home with sustainability at its core. The "labor of love" came together after eight months of work with help from builders Kevin Smith and Taylor Thompson of Taylorsmith Sustainable Construction. 

An architect and construction engineer couple build a sustainable, 624-square-foot abode for $221,580 in their Southeast Portland backyard.

Named after its pinwheel-shaped plan, the Pinwheel ADU is framed with FSC-certified timber and clad in local, sustainably sourced Western Red Cedar. For energy efficiency, ZIP System® R-sheathing was used for continuous exterior insulation and weatherproofing, while large, high-performance glazing lets in an abundance of natural light.

To help create the illusion of more spaces, the great room features a vaulted ceiling and opens up to the outdoors with 12-foot wall-to-wall glazed sliding doors.

A Cozy Studio Tops an L.A. Garage for $220K

When California lawmakers made it easier and more affordable for homeowners to build Accessory Dwelling Units (ADUs), one Los Angeles family, a young couple with two small children, turned to local architect Martin Fenlon to create a compact and sustainably minded studio apartment atop their detached garage in Los Feliz.  Working with a tight timeframe of just a little over a year, Martin crafted the 350-square-foot addition—named Rodgers ADU after the clients—for a total cost of $220,722. He also enlarged the garage to 400 square feet for extra storage space. 

"Clad in economical fiber-cement siding, the ADU reaches down to the ground, while the stucco cladding of the garage reaches up, forming a semi-enclosed entry sequence," says Martin.

To create a spacious feel, Martin installed large, double-glazed windows and a Velux skylight. "The windows, together with the operable skylight, act as a solar chimney to passively cool the space," he notes.

A Garage Becomes a Renaissance-Inspired Studio for $102K

In the backyard of a downtown Toronto home, local design practice Anya Moryoussef Architect transformed a single-car garage into a multifunctional, light-filled workspace that cleverly belies its compact 325-square-foot size for just under $102,000. The client—a former architect who now works from home as a screenwriter and art director—set high demands for the small space. He requested not only a workspace and a separate sitting room, but also plenty of storage for his art collection and scripts, as well as room for his golden retriever, Ollie. 

The exterior of the Crawford Studiolo is made of Inax porcelain mosaic tile and Brampton Brick concrete blocks.

To divide the garage into four rooms without creating an uncomfortably cramped experience, the architects and client found inspiration in the 15th-century studiolo at Ducal Palace, a Renaissance-era architectural triumph in Gubbio, Italy, renowned for its illusionistic wood paneling.

The view from the work room and sitting room towards the entry and the back of the house.

A Playful, Postmodern ADU in Los Angeles Is Built for $249K 

"A sense of expansive space and careful use of light and color are things that make our ADU designs feel large, even when most of them are under 800 square feet," explains designer Bo Sundius, who co-founded Los Angeles–based Bunch Design and Bunch ADU with his wife Hisako Ichiki, also a designer. This surprisingly lofty, 850-square-foot ADU that the couple designed for a backyard in the Highland Park neighborhood of Los Angeles is the perfect example of how small spaces don’t have to feel so small. To make the two-bedroom, one-and-a-half-bath dwelling look and feel as large as possible, Sundius and Ichiki maintained sightlines from one end to the other, placing the bathroom and the water closet in box-like volumes that are inserted within the house’s overall volume. They also used the long lines of the stepped ceiling to make the space feel much more expansive than its square footage might suggest.

A stepped drywall ceiling lends texture and interest on the interior. The open-plan public space, which includes the kitchen, dining area, and living room, is sectioned by a pair of box-like volumes that contain the two bathrooms; the two bedrooms are located at the rear of the house.

Taking inspiration from iconic architectural designs, such as Italian modernists like Ettore Sottsass and Gio Ponti, and the work of Mexican architect Luis Barragán, they added a playful feeling to their design and inserted color throughout the home.

Sundius and Ichiki employed a white-painted, stepped ceiling that's made from drywall and reflects a bright, yellow wall and door and the pink tone that accents the bathroom skylight.

Sundius and Ichiki sided the home with sand-colored stucco that ties to the other stucco-clad homes in the neighborhood.

A Laser-Cut Steel Addition Sharpens Up a Michigan Home For $85K

After moving from Chicago to the cozy college town of Ann Arbor, one couple, Sharon and Robin, were eager to infuse a touch of urban sensibility into their new home. Built in 1914, the protected-status house had a detached two-story garage that they felt could be improved by building a contemporary addition to connect the structure with the main house. Sharon, a University of Michigan professor of architecture, was well-aware of Ann Arbor’s strict regulations on altering historic district-protected buildings, so she reached out to Kasey Vliet, the Principal of KASE Studio, who was a teaching colleague at the university. Combining requests from the couple and the historic district, KASE Studio successfully crafted a multifunctional 206-square-foot addition with an abundance of glazing—to promote views of the original architecture and the outdoors—that could also be easily removed should a future owner wish to return the home to its original form.

Custom steel panels wrap around the bistro nook. The hallway flooring is poured-in-place concrete. 

Sharon designed the concrete patio and a new rain garden (which treats all stormwater on site) in consultation with her neighbor, who is a landscape architect. KASE and Sharon worked together to integrate the two spaces into the new design.