A 26-year-old built a $260,000 ADU on her family's property. Now, she lives in the 748-square-foot space with her sister.

Mia Corippo has learned a lot about real estate and saving money from her parents over the years.

Corippo, 26, grew up just outside Yosemite with her tight-knit family. The teacher, coach, and content creator lived in Orange County for a few years for college, but she moved back in with her parents in 2021.

"My parents have always been really big on us living with them and saving up money for as long as we can," Corippo said of why she lived with her parents, adding that her brother did the same. "We've had the privilege of living with them when we came back from college and building our savings."

Corippo said her parents also instilled in her lessons about how real estate can set you up for financial success. When she was in high school, they turned a portion of their garage into an Airbnb. They let Corippo and her sister handle the housekeeping for the unit to help pay for their club volleyball, teaching her early that real estate could be a valuable asset.

In late 2023, her family took those lessons and built a small home on property near Yosemite.

Corippo's parents had purchased a small piece of land near the national park in California when real estate prices were low, unsure what to do with it.

When they started toying with the idea of building a cabin on the land, Corippo, her brother, and her sister decided to pool their resources and invest in the build with her parents.

"When we were little, my parents invested in Apple stock, which they bought for nothing," Corippo said. "We used those Apple stocks in our savings to invest in this first home."

The 650-square-foot house became a family project. It had one bedroom, a separate lofted sleeping area, and one bathroom. Corippo and her father told Business Insider the build cost around $300,000, which included creating a well, septic tank, and driveway on the property. Corippo moved into the finished space in 2024.

"It was definitely a family collaboration of making it somewhere I could live, but also something that would be an investment once I moved out," Corippo said.

Then, Corippo decided she wanted a house for herself on their land.

Corippo's family hoped to eventually rent out the primary residence on the property, so she knew she wouldn't live in it forever. She still had a decent amount of savings from living with her parents for a few years, giving her options for her next move.

"I had still saved enough money to make something of my own," Corippo said. "Nothing crazy. I could probably make a small down payment on a really small house."

Corippo could have bought her own place, but her dad had another idea: She could build an accessory dwelling unit (ADU) on the same property. She would have her own space, but she wouldn't have to buy more land and could share the well already built on the property, saving her money.

Corippo loved the idea.

She designed her ADU by tweaking the blueprint for the first home on the land.

Corippo loved much of the main house's layout, but she made some changes to her ADU to better suit her lifestyle.

"We basically took the same blueprints, and we added a laundry room and another bathroom and then built another one right next to it," Corippo said.

Corippo's ADU has two private bedrooms and bathrooms, and was specifically built to be 748 square feet to avoid hefty encroachment fees associated with building in her area. She said her fee was only $300 because her ADU was under 750 square feet.

The ADU was completed in May 2025. Now, Corippo lives in it with her sister, her two cats, and her dog.

She knew she wanted her house to have a classic cabin feel.

Although her house is small, Corippo didn't want its size to dictate her approach to interior design.

"Just because my house is small, it doesn't mean that it can't have that charm to it, or I can't do extravagant things on the inside," she said. "I always say I like to lean into the small."

Corippo said she followed her parents' lead in some ways with her approach to the design. They drew inspiration from The Ahwahnee hotel in Yosemite National Park when designing their home, and Corippo thought looking to historic buildings in the area for her own space just made sense.

"I've just been taking inspiration from my parents and historic buildings near Yosemite, and the endless cabins that I've stayed in, and just trying to put that into a small ratio," she said.

She also wanted the house to feel natural in the landscape, painting the exterior a deep green called Muddled Basil from Sherwin-Williams.

"We really wanted to stay true to where we live, so we went with a deep dark green for the outsides," she said.

A Dutch door set the tone for Corippo's home.

One charming design element Corippo knew she wanted in her house was a Dutch door.

"When I lived in the other house, I kept the door open a lot," she said. "I just realized in a small space and living in California, where 70% of the year it's great weather, I needed to bring the outside in."

She painted the door a bright red, adding a pop of color to the interior and contrasting with the green exterior.

A mudroom sits right near the entrance to Corippo's home.

The first house Corippo's family built on their land didn't have a laundry room, but it was important to Corippo to add one since she would be living there full-time.

Her washer and dryer are both full-sized but stack on top of each other, saving space. She also has a countertop in the mudroom, where she stores her cats' items behind a colorful curtain.

The living room and kitchen take up much of the home.

The kitchen and living room are in an open-concept space in the center of the home. Corippo covered the walls with wood paneling, while the flooring is concrete.

"It's just a concrete slab that we sealed and polished," Corippo said, adding that she got the idea from her parents, who did the same in their own home. "It kind of adds a little bit of outdoorsy element because it looks a little bit like stone."

The space also has a couch and a breakfast nook, which Corippo said is her favorite spot in the house because she can see through her Dutch door when she sits there.

She also chose not to get a TV to conserve space and avoid making it the focal point of the room.

She got creative to ensure she could achieve the look she wanted at the right price.

Professionals framed out Corippo's kitchen, which has a dishwasher and open shelving.

She also did some work herself to ensure her vision came to life at the right price. For instance, Corippo wanted butcher block countertops, so she found a set on Facebook Marketplace to save money.

"When I splurged, I also found ways to kind of be creative about what I was paying for," Corippo said.

Her dad also did the wood backsplash in the kitchen, which helped her save as well.

She wasn't afraid to learn new skills as she built the house, either.

Corippo wanted to add a fireplace to her space because she thought it would really evoke the cabin feel she wanted the home to have.

"Every old house here has such a beautiful fireplace or some sort of brickwork or woodwork," she said. "So I kind of took inspiration from those things."

The renovation was getting pricey, though, so Corippo ended up completing it herself when her budget got tight. She hadn't done a project like that before, but she figured it out on the job.

The house has two bedrooms, one of which could be blocked off to be a more private space.

Corippo's home has two separate bedrooms, one at each end of the house. Corippo's bedroom is down a hallway off the living area, and she has a bathroom in the hall.

Meanwhile, her sister's room is off the mudroom and has a private bathroom. It also has its own entrance, so if they closed up the wall between the mudroom and the bedroom, it could become a private space that the Corippos could rent out if they wanted. They like that the additional entrance keeps their options open.

Corippo made her bathroom feel high-end despite the small space.

Many tiny homes or ADUs opt for showers rather than baths to save space, as the Corippos did in the second bathroom of their ADU, but Corippo knew she wanted a luxurious tub in her own bathroom.

"I absolutely love baths," Corippo said. "Our contractor at the time was like, 'You don't want a clawfoot tub. And I was like, 'Yeah, I do.'"

She and her dad also added wood panels to the walls around the tub after seeing similar spaces on Pinterest, giving it a high-end cabin feel. It's one of her favorite rooms in the house.

All in, Corippo's ADU cost around $260,000 to build.

The construction of Corippo's house was quoted for $205,000, but she also needed to connect a driveway and septic tank to her home since the first house wasn't built with the second home in mind. Those added costs brought the project closer to $260,000, as she told Business Insider.

Still, Corippo said opting for an ADU rather than buying or building on new land likely saved her at least $100,000.

"Most houses I was looking at when I had my savings were more in the $350s or $400s range, because we are so close to Yosemite, and it's California," Corippo said.

In addition, Corippo said her mortgage is fairly affordable at $2,000 a month. She also splits that cost with her sister, so she's paying just $1,000 monthly, which is about $1,500 less than the average rent in her area, according to Zillow data.

She loves her house, but Corippo said there are still a few things she wishes she had done differently.

Although Corippo tried to treat her ADU like a typical house, there were some hiccups she ran into because of how small the space is. For instance, the height of her windows prevents her from adding furniture to some spots in the house.

"The windows are pretty low, so I can't really put anything in front of them," she said. "So I feel like I kind of lose that space."

The ADU also has wall units instead of a central AC unit, and she regrets that the unit in her living room is in a conspicuous spot.

She also wishes she had thought about her curb appeal earlier in the building process, but her mom is helping her get her garden started now.

Corippo doesn't see herself leaving her ADU anytime soon.

Corippo has visions of renting out the ADU someday, but for now, she is loving living with her sister and being so close to her family.

"As long as I'm single and have no kids, I'll probably stay in that house," Corippo said. "But then again, that house could easily house a kid someday. It's got two bedrooms."

Corippo recommends embracing ADU life over buying a traditional home for people who have the option.

"If people have the means to build on family land, I definitely would say take the chance and do it," she said. "Even if you live in that house or that ADU for a few years or a year, it's still going to put you ahead because you're spending so much less instead of buying in the crazy housing market."

"I know that's not an option for everybody to have a house and pay a mortgage," she continued. "But living with your family as long as you can and building on their land is such a life hack if you have the option."