How a struggling single mom built an ADU, without killing a 60-year-old tree

A tree is framed by a raised window in a living room.
A raised window in the ADU offers views of a 60-year-old Chinese elm.
(Carolyn Cole / Los Angeles Times)

When Chantal Arnoult moved with her family to France in 2008, she had no idea she would return to Los Angeles four years later, divorced and unable to afford the home that she and her then-husband had purchased for $395,000 in 2002.

“I was broke, with two kids and no job,” she said. “I had a long-term renter, so I stayed with my sister and then rented another place. When I refinanced the house, I still couldn’t afford the mortgage, so I rented my house on Airbnb for five years. My kids and I moved seven times. It was a constant juggle.”

When a new series of California laws was passed in 2017 to make accessory dwelling units, or ADUs, easier to build, Arnoult decided to move home, withdraw her retirement funds and build a 650-square-foot income property in her Mar Vista backyard.

A two-story ADU with raised windows to maximize privacy and light.
Raised windows maximize privacy and light.
(Carolyn Cole / Los Angeles Times)


As conceived by her sister, Venice architect Isabelle Duvivier, the ADU plays out as a case study in the efficient use of space and a thoughtful approach to preserving the tree canopy.

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“We are losing our tree canopy due to development,” said Duvivier who serves on the city’s Community Forest Advisory Committee. “People are sacrificing every ounce of open space to make these big boxes. It’s OK to build, but build with nature. Ninety percent of our tree canopy is on private property. Trees provide shade, clean the air, collect rainwater and connect us to nature. As our city gets hotter, it is even more important to save trees. I’m a building designer, but I feel like a building is meaningless without a connection to the outdoors.”

The home also is an inspiration for anyone trying to balance the economic struggles of trying to live, work and raise a family in Los Angeles.

A living room, photographed from the kitchen
Sunlight streams through the windows and French doors of the ADU.
(Carolyn Cole / Los Angeles Times)

“I worked hard to make it affordable,” Duvivier said of the ADU, which was completed in 2019 for approximately $225,000 including pavers, landscaping, fencing and an attached garage conversion that shares a wall — and can also be rented out. “Most of my ADUs are coming in at more than $300,000. This one is the least expensive one that I’ve built, in part because Chantal went with the cheapest bid. But I think it’s a beautiful unit.”

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ADUs are complicated, Duvivier said, because they are on small lots and “everyone wants a roof deck and two bathrooms in a tiny space.” They are also complicated by things that people often don’t consider, like the fact that new homes must sit five to six horizontal feet from power lines. “ADUs are often closer to the power lines, so you have to get approval from the LADWP, and they are overwhelmed with ADUs right now. In the old days, new buildings would have to be 15 feet from power lines, but now it’s five.”

A woman sits on a couch with a tree visible through the window behind her.
Architect Isabelle Duvivier with a view of the Chinese elm she worked to preserve over her right shoulder.
(Carolyn Cole / Los Angeles Times)

Despite being two stories tall, the ADU is dwarfed by an enormous 60-year-old Chinese elm that the sisters worked hard to preserve. “I like using two stories because you can never get the land back,” Duvivier said. “We had to cut the Chinese elm back slowly, and then, when we were finally ready to build, we gave it a good trim. Now it enhances her yard.”

It also enhances the ADU, which is airy and bright, thanks to its southern exposure and soaring 18-foot ceilings that make the interior feel larger than its floor plan. “It feels voluminous even though it’s tiny,” Duvivier said. “I pay attention to the orientation of the sun to make sure buildings are maximizing the free energy they get from the sun and stay cool from windows that face south.”

Because Arnoult was concerned with her neighbors’ privacy, Duvivier designed the building with raised windows that look out on the Chinese elm and other trees and offer light and privacy. “You don’t see out, you see up,” Arnoult said. “I actually call the ADU ‘Window Onto the Trees.’ The beauty of these windows being up high is that you get light and nature.”

A Chinese elm is seen through the square windows of a living room.
A Chinese elm is visible through the windows of the living room of the ADU.
(Carolyn Cole / Los Angeles Times)

Another environmentally friendly touch by Duvivier, whose own Venice home won a LEED Platinum rating, is the addition of a 400-gallon cistern located behind the house so that her sister can use reclaimed rainwater to water the lush landscape. “We always collect stormwater on-site and collect more than the city requires,” she said. “I try to integrate it in the design so that people can really use it and not just have rain barrels because the city requires them for new buildings.”


The rental unit has two small bedrooms upstairs, including one with a half wall that overlooks the living area. Downstairs, there is a bathroom, laundry and a kitchenette (featuring cabinets and miniature appliances from Ikea) that opens onto the living room. Oversize French doors let more sunshine in and provide easy access to a private patio and garden that is hidden behind a fence that separates the two homes.

The interiors feature concrete floors that are durable and pet-friendly (therefore making them perfect for renters), and Arnoult estimates that she is close to paying off the ADU with the proceeds from short- and long-term rentals. She’s furnished the space simply with an Ikea sleeper sofa and chaise with built-in storage; bar stools found on Nextdoor; a statuesque fiddle-leaf fig; and accessories from rummage sales and Wayfair.

A kitchenette with miniature appliances.
The kitchenette features miniature appliances.
(Carolyn Cole / Los Angeles Times)

Looking back, Arnoult said she regrets hiring the contractor who offered the cheapest bid because she ultimately had to hire subcontractors to install central air and heat, rain gutters, landscaping, stair railings and fencing and build out the kitchenette. “It may have been less stressful if I had included everything in one higher bid,” she says now.

A bathroom sink, toilet and shower
Even the bathroom offers a view of the trees.
(Carolyn Cole/Los Angeles Times)


And although she has no regrets about building the ADU, she admits she was surprised when her taxes went from $6,000 to $9,000 a year. She also thinks it’s important for people to understand L.A.’s Rent Stabilization Ordinance, which regulates rent increases and evictions in a city where rents are among the nation’s highest.

Due to COVID-19, L.A. landlords are prohibited from raising the rent on rent-stabilized units until 2023. “People who are considering building an ADU should be aware that if their house was built in or before 1978, the Housing Department will turn their main house or the entire property, depending on the configuration, into an RSO [rent stabilization ordinance] property. This should be more transparent.”

Looking down at the living room from a half wall bedroom/loft.
Looking down at the living room from the second-story bedroom.
(Carolyn Cole / Los Angeles Times)

Like many L.A. stories, Arnoult’s ADU is a saga of economic hardship intertwined with valuable real estate.

“I don’t know if I could have held on to my house if I didn’t have the supplemental income from my ADU,” she said. “I feel so lucky to own this house. I won’t sell it. I have two kids, and now I have two houses. If anything happens to me, both of my kids will have a place to live. I don’t think my kids would be able to afford to buy a house in L.A.”

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Acknowledging how difficult it is for so many people to find affordable housing in Los Angeles, the renovation, she said, has left her humbled and grateful.

“When I was at plan check, I was standing in line with single moms and retired people who were building ADUs because they needed the extra income. Short-term rentals change people’s lives. It gives them the financial freedom to live in Los Angeles. I was lucky. I owned a house. I had money in the bank. My house saved me.”

A bed and side table.
Raised windows in every room look out to the trees.
(Carolyn Cole / Los Angeles Times)

How to make ADUs more tree-friendly

In order to preserve trees during construction, it helps to understand their value. “Trees, unlike buildings, take many, many years to get established,” explained Duvivier. “The older the tree, the more valuable it becomes. Trees are one of the only infrastructures that increase in value over time. The City of Los Angeles is working to change the course, but trees take a long time to grow, so trees we plant now won’t benefit us for 50 years. It is most important to save mature trees.”

According to a 2017 study by USC’s Spatial Sciences Institute, some neighborhoods of Los Angeles have lost up to 55 percent of their tree canopy. Things haven’t gotten better since then, Duvivier said, thanks to “development, lack of maintenance, and droughts.”

Here are her recommendations on how to preserve trees during construction:

— When building around trees, install a protective fence around the tree so that contractors don’t accidentally bump into the tree. Avoid placing building material under the tree canopy, “because that removes the air space around the roots and can kill the tree,” Duvivier said.


— Duvivier advises watering trees more often than normal during construction to reduce tree stress. Adding three inches of mulch to the base of trees will also help.

— Don’t trim large branches all at once.

— If you need to dig around a tree, it is smart to leave large roots intact and dig around the large roots with hand tools. “Cutting a large root should only be done if absolutely necessary,” Duvivier said.

For more detailed resources about trees, consult the city of L.A.’s Community Forest Advisory Committee site.

A Chinese elm and rainwater collection tank located behind a house
A Chinese elm and 400 gallon cistern located behind the ADU.
(Carolyn Cole/Los Angeles Times)