• UK-based architecture firm Koto makes cabins that are available in the US for the first time.
• The Niwa collection of minimalist tiny homes comes in four sizes from 67 to 403 square feet.
• The sleek cabins, priced from $52,000 to $187,000, could be used as a backyard office or a sauna.

Call it a cross-cultural connection: Koto, a UK-based tiny-home firm that fuses Scandinavian and Japanese design, is now delivering to US customers.

Founded in 2017, Koto specializes in cabins, modular homes, and sculptural small-scale architecture for residential and wellness-focused spaces, including hospitals. Its flatpack collection, Niwa, is a series of sustainably crafted cabins that can be delivered as panels and assembled on-site.

"Our designs are like Ikea," Koto cofounder Jonathan Little told Business Insider. "But instead of a box, they go into a container. They can be shipped around the world and installed pretty much anywhere."

The Niwa comes in four sizes: small (67 square feet), medium (135 square feet), large (269 square feet), and extra large (403 square feet). Prices range from $52,000 to $187,000, with additional costs for custom features and upgrades. It is the brand's first modular design that is available worldwide.

Following a consultation, customers can purchase a design license from Koto, priced between $938 and $2,152. This cost is not included in the cabin price and is refunded after the cabin is purchased. While clients are responsible for securing permits and hiring local contractors for site prep and installation, Koto offers support throughout the process. It can also be hired for concept site design and landscaping.

Each Niwa unit is constructed in a European factory and shipped to the US in panel form. Depending on the location, it is delivered via truck, helicopter, or boat.

Koto began shipping Niwa units — which can be used as backyard offices, saunas, gyms, guest houses, Airbnbs, or anything else — to the US in April. It has already built units for customers in Massachusetts and has other planned installations in Los Angeles.

Tiny homes — also known as accessory dwelling units, or ADUs — are popular across the US. Several states, including California, Vermont, and New York, even offer grants to help homeowners build them on their properties. For some, ADUs provide a more affordable path to homeownership. For others, they offer an income-generating opportunity through rentals or a practical way to create additional living space when the square footage in a main house is limited.

"We're seeing such a diverse requirement for our cabins, both from private individuals all the way up to hotel owners," Little said.

Take a look inside the three Niwa models available in the US.

The design of the Niwa cabins channels clean, contemporary minimalism.

Each Niwa unit has essential features, lighting, and a heating and cooling system. Depending on the size of the unit ordered, a bathroom or kitchenette can also be included.

Koto designed the Niwa collection of tiny homes with nature in mind.

Niwa units are designed to blend into their surroundings and support both on-grid and off-grid living.

Koto builds its cabins using natural materials. The structure is built with sustainably sourced timber. Meanwhile, the exterior cladding is made from Shou Sugi Ban timber — wood treated with a traditional Japanese charring method that makes it fire-resistant.

Koto builds its cabins using natural, sustainably sourced materials. The main structure is made from responsibly harvested timber, while the exterior features Shou Sugi Ban — wood charred using a traditional Japanese method for added durability and fire resistance.

Interior finishes vary by unit type; studio cabins and units people can sleep in typically feature oak or birch plywood, while saunas are finished with hemlock, spruce, or cedar.

Koto wants the people who buy its homes to reconnect with the outdoors.

Little told Business Insider that Niwa's nature-centered design was inspired by his own move from busy London to Norway, where the pace of life is slower, and there's a greater emphasis on the outdoors.

"London has a real fast-paced life," he said. "You work a lot of hours, then go home, rest, and do the same thing the next day. Moving to Norway was the opposite. It was like, yes, get your work done, but be outside with your friends and family, be in the woods in nature."

Each cabin can be installed in under a month.

Niwa cabins typically take eight to 12 weeks to manufacture, with shipping adding another two to four weeks, depending on the destination.

Shipping costs vary by location, but the company estimates US deliveries cost around $9,000.

According to Koto's website, installation for each unit may take four to 14 days.

The collection comes in four sizes: small, medium, large, and extra-large.

According to Koto, the Niwa small unit, which measures about 67 square feet, is ideal for use as a studio or sauna. The ceiling height ranges from 5.9 feet at its lowest point to 11.8 feet at its peak.

The design license fee for this unit is about $940, and the base price starts at $55,286.

The cabins' interior design is simple yet stylish.

The interior finishes of the Niwa units typically feature wood and soft, earthy tones like browns and greens.

This medium-sized Niwa cabin comfortably fits up to six people when used as a sauna.

A medium-sized Niwa measures about 135 square feet and can include a kitchenette, a small bathroom with a shower, and a bed. It's best suited for a single-room sleep cabin, studio, or sauna.

According to Koto, the cabin makes an ideal private office or garden studio. If used as a sauna, it features upper and lower benches with tiered seating for six to eight people. The sauna also includes a separate changing area.

The licensing fee is $1,603, and the cabin's base price starts at about $72,957.

Koto also sells furniture for its cabins.

Customers can also purchase furniture packs from Koto for an additional price. These packs, which range from $7,119 to $9,379, include items like lights, couches, desks, chairs tables, and shelves.

The large Niwa has space for a full-size bathroom.

The large Niwa cabin offers enough space for a living room, a kitchen, and a full bathroom with a shower. Like the smaller models, it's ideal as an office or sleep cabin and can also be used as a gym, according to Koto.

The unit measures about 269 square feet, has a licensing fee of $2,156, and starts at $116,100.

The extra-large Niwa comes closest to a traditional ADU structure.

With 403 square feet of space, the XL Niwa cabin is well-suited as a self-contained studio, gym, or guesthouse. Its generous size makes it the closest match to a traditional ADU within the modular flatpack collection and the best option for long-term stays.

Its licensing fee matches the large model at $2,156, with pricing starting at $187,000.

"I think this one is closer to the ADU market, while the slightly smaller models are better suited for Airbnb or hotel use," Little said.

• Justin Mauldin built an accessory dwelling unit, or ADU, in his Austin backyard for $41,500.
• Mauldin said the ADU office allows his family of four to live comfortably in a smaller home.
• The ADU also boosted his home's property value, according to his real-estate agent.

This as-told-to essay is based on a conversation with Justin Mauldin, 40, who built an accessory dwelling unit, or ADU, in his Austin backyard. The interview has been edited for length and clarity.

I'm the founder and CEO of Salient, a PR agency that partners with tech startups.

By 2019, before the COVID-19 outbreak, my team had already shifted to a mostly remote setup, with many freelancers working from home or shared office spaces like WeWork. My wife and I decided to make the most of our property and build a dedicated home office.

Our property is within Austin city limits. We live on a quarter-acre lot with a relatively small main house of about 1,200 square feet. At the time, our large backyard was undeveloped, with only a small farmhouse shed on the property.

We added an accessory dwelling unit of just under 200 square feet to our backyard. The cost for the ADU was $32,542, which covered the products, shipping, and installation. I believe prices have increased since then, but we were able to take advantage of a sale and a 10% discount at the time. The total cost of the entire project was about $41,500.

It's been the best decision we could have made for our property. We purchased our home in 2020 for around $450,000, and its value has definitely increased. When we asked our real-estate agent for an estimate, she said it could be worth $750,000 today. (Editor's note: The median home price in Austin has increased 12.8% since 2020, according to Redfin.)

Working from the ADU has been fantastic — it's allowed me some quiet time. We have two young children, so I can "go to work" without being in the main house with all the chaos and noise. It's truly been a game changer.

The construction process was simple and fast

Even though it's separate from the main house, the home office is the most beautiful room on the property — everyone who sees it is completely wowed.

I went all out with super-tall, dramatic ceilings and a massive wall of windows. We also built a fire pit in front, which has become a real focal point.

When we decided to build an ADU, COVID made it difficult to get bids, materials, and reliable contractors, so a pre-fabricated option seemed like the best choice. I went with Studio Shed, a Denver-based company that builds the structure in their warehouse and then ships it to be assembled on-site.

The process was simple, like building with Lego bricks or designing a car. You pick your model, customize the size, ceilings, and windows, and select your upgrades. You can go as basic or as fancy as you want. It's all done online — just like ordering anything on Amazon — and you get the price immediately.

Before the ADU arrived, I cleared the site and poured the concrete pad, which cost about $1,500.

When it was delivered, I didn't want them to just drop off the materials and leave me to figure it out, so I paid a few thousand dollars for them to assemble the structure. The walls, windows, and roof were up in just two days.

After the structure was assembled, a local handyman and I worked on the finishing details, including installing the flooring, painting, adding door handles, electrical work, and other touches. Since the ADU was too far from the main house to connect to our central AC, I also added a mini-split system that I purchased for $600 and paid about $500 to install.

Everything was built and finished quickly. The ADU was delivered on February 1, 2021, and completed by the end of the month.

The ADU allowed our family of 4 to live more comfortably in a smaller house

Given the price of our home, it's clear we're not in a fancy, McMansion-filled neighborhood. Most homes here are 1950s bungalows.

When we first moved into our home, instead of following the common trend — where people tear down these homes to build new constructions — we took the opposite approach.

We wanted to preserve the character, so we did a lot of renovations: replacing the siding, repainting, completely redoing the interior, and reworking the landscaping. I think the neighbors really appreciated that.

Still, we have two girls, so a 1,200-square-foot home with just one bathroom can be a challenge, especially when we have visitors.

Of course, we'd love a bigger home, but with prices still unaffordable, it's tough. When we bought our home, our interest rate was locked at 2.5% — rates now are much higher. Most homes in desirable areas are in the $1.5 million range, and with the high property taxes here, it's just not realistic. We could not afford a place in Austin now without doubling or tripling our housing costs.

For now, we're happy with our place, and maybe we'll add a bathroom one day.

ADUs are becoming popular in Austin, and I can see why

Austin has a housing crisis, yet people still want to live here and continue moving to the city. I think creative solutions like ADUs are necessary.

Over the past few years, the city has made it much easier to add ADUs to properties, especially the type I built, which is under 200 square feet.

Historically, with a permit, you could divide a quarter-acre or smaller property into two lots — one for your main home and the other for an ADU, often for uses like Airbnb. But now, with relaxed regulations, you can simply add a small structure in the back of your property without needing a permit.

While some may have concerns about homes being closer together, I believe this is the best solution for making it easier for people to build ADUs and own homes — and it's working well.

The office has certainly made living in our house much more comfortable.

In today's world, there's so much background noise, whether you're at the office or working remotely, making it hard to focus and be creative. You can try blocking it out with headphones, but there's a big difference between that and being in a truly quiet space.

I'm used to my kids running in and out — that's just part of being a dad — but when I close the door, it's so serene.

Beyond avoiding interruptions, sometimes you just need real focus time, especially for the creative stuff. With all the noise around us, having a quiet space feels like a complete escape.

• New York City recently made it legal to add a housing unit to certain one- and two-family homes.
• But both city and state regulations will drastically limit construction, experts say.
• A state law severely restricts the addition of ADUs to two-family buildings.

One of the solutions to New York City's housing shortage — adding extra units in attics, basements, and backyards — is already running into a slew of regulatory hurdles.

Under the city's zoning reforms, certain one- and two-family building owners will be allowed to add a so-called "accessory dwelling unit" to rent out, house a family member, or live in themselves. Homeowners could boost the value of their property and bring in extra income while creating more homes in a city facing a dire housing shortage. The change would also help bring many of the city's tens of thousands of existing basement units into compliance with health and safety codes.

But the city's new law restricts ADUs in several ways, including by banning ADUs on lots with attached rowhomes or townhouses and on lots more than half a mile from a mass transit station. The law also prohibits ground-floor and basement ADUs in areas prone to coastal flooding and inland flooding during heavy rain. A backyard ADU can cover no more than a third of the yard and can't be added in historic districts.

A state law that could block a lot of building

ADUs aren't just subject to city regulations. New York State's Multiple Dwelling Law (MDL) requires that buildings with three or more units have features one might associate with a large apartment building. For example, the law requires sprinklers in every unit and a certain ceiling height in basements, both of which can be prohibitively costly to add to an existing building.

"A lot of the sites that might be able to add an ADU would trigger the MDL and, therefore, wouldn't really be viable from a design perspective," said Marcel Negret, the director of land-use planning at the Regional Plan Association, a pro-housing nonprofit focused on the tri-state area.

Casey Berkovitz, the press secretary for the Department of City Planning, said the City is still examining how the MDL will apply to ADU construction, but agrees it would make it harder to add basement and attic ADUs in existing two-family homes.

There are exceptions. Building a new detached ADU wouldn't implicate the MDL because it's not part of an existing building, Berkovitz noted. And certain neighborhoods across the city are part of a new basement legalization effort that exempts them from certain MDL restrictions.

The state legislature could amend the MDL to reduce barriers for ADUs in New York City — something the City has asked it to do, said Eric Kober, a senior fellow at the conservative Manhattan Institute and former planner with the City. But he's not optimistic state lawmakers will get on board, adding, "There's no indication that it's on their radar or something that they're interested in doing."

Kober argued that the City's requirement that homeowners live on the lot they add an ADU is the most counter-productive of the regulations because it would prevent private developers from building ADUs.

The NYC government last fall said it expected that fewer than one in 200 eligible homeowners would choose to add an ADU to their property in a given year.

Negret estimated just a few thousand of the 82,000 additional homes the city is expected to add over the next 15 years under City of Yes will be ADUs. That's down from between 26,000 and 40,000 ADUs the city expected to add under the original version of its reforms, which were significantly reined in by the city council.

"My conclusion is, yes, ADUs are technically legal, but there's still a long, long way to go before they could be a much more significant share of a growing housing stock," Negret told Business Insider.

Legalization is just the first step

The city is still developing new rules that will impact ADU construction. This includes creating updated flood maps, which will likely further restrict where ADUs are allowed. It's unclear when the City will finalize the rulemaking process.

Eventually, the City says it will create a "one-stop shop" website to guide homeowners through the ADU construction process, including a set of pre-approved designs.

New York is following in the footsteps of cities such as Los Angeles and Seattle that view ADUs as low-hanging fruit in the quest for more affordable housing. After California loosened its restrictions on ADUs, the extra units made up nearly 20% of new homes built in 2023.

But progress tends to be slow. ADU legalization alone isn't usually enough to prompt lots of new construction. In some cities and towns, local land-use laws, permitting, and other regulations have stood in the way. Owner-occupancy requirements, off-street parking mandates, and discretionary permit reviews are among the most burdensome rules.

Just over a year ago, the NYC government rolled out a pilot grant program — called "Plus One ADU" — that awarded 15 homeowners with up to nearly $400,000 in funding per household to build an extra dwelling in their backyard, basement, or attic. The city has since expanded that program, but it applies only to lots that are already zoned to accommodate another unit.

"ADUs are a proven tool in cities across the country to support working families with extra space, additional income, and the opportunity to age in place," Dan Garodnick, the director of the New York City Department of City Planning, told Business Insider in a December statement.

• Sue and Ken Allen's Palo Alto home, bought for $63,000 in 1975, is likely worth $3-4 million.
• The threat of capital gains taxes and higher property taxes discourages them from selling.
• Instead, they're planning to downsize to a tiny home accessory dwelling unit in their backyard and rent out the main house.

Sue Allen and her husband, Ken, moved to Palo Alto in the 1970s, just as the South Bay was beginning to be known as Silicon Valley.

Allen, 75, and her husband, 77, bought their home in South Palo Alto for about $63,000 in 1975. These days, surrounded by Stanford University and the headquarters of a slew of the biggest tech companies in the world, the home is likely worth close to $4 million.

The home is large — in the mid-1980s the couple added a second story to the house to accommodate four additional bedrooms and two bathrooms as their family grew.

In the early 2000s, they rebuilt the single-story cottage in their backyard — also known as an accessory dwelling unit — to include a bedroom, kitchen, and bathroom. They've rented out the cottage ever since.

But the Allens have no plans to sell their home, despite the fact that it's larger than what they need. That's because they plan to eventually downsize to their backyard cottage and rent out the main house.

The Allens aren't alone in relying on an ADU for housing in their older age. Backyard tiny homes — or other accessory units in basements or attics — are an increasingly common way for homeowners to add living space, boost the value of their property and earn extra income through rent, and even create a place to age in. California is one of 14 states that have broadly legalized ADUs and more than 60,000 have been permitted in the state since 2016.

When selling will cost you

In addition to having a backyard home to downsize to, it doesn't make much financial sense for the Allens to sell their property and buy a smaller home to age in.

If they sold the property, they'd be on the hook for hefty capital gains taxes, which apply to couples who make more than $500,000 in profit and individuals who make more than $250,000. They'd also likely have to pay significantly higher property taxes if they purchased a new home, not to mention a relatively high interest rate on any new mortgage.

Like other California homeowners who purchased their properties decades ago, the Allens benefit from exceedingly low property taxes as a result of Proposition 13, which mandates that property taxes are just one percent of the home's purchase price and can't rise by more than two percent each year until the next sale.

The California law has contributed to the so-called homeownership "lock-in effect," which intensifies over time as home values rise and the property taxes someone would have to pay on a newly purchased home rise.

"We're living in this $4 million house, and we don't downsize because it's kind of not worth it," Allen said. "We'd have to pay so much in taxes."

Allen's story reflects a broader trend of boomer homeowners who've grown significant wealth through their home equity. And she's quick to acknowledge that she's both benefited from and perpetuated "generational wealth" through homeownership. She could afford her own $12,500 downpayment only with help from her mother. In turn, she's helped her five adult children with their down payments. But the Allens' kids have all left California to live in other states — Texas, Idaho, Utah, and Nevada — where housing is more affordable.

Zillow estimates the Allens' property is worth about $3.1 million, while Redfin puts it at nearly $3.5 million. Allen thinks it could be sold for closer to $4 million, based on what similar homes in her neighborhood have fetched in recent months. A much smaller home down the street from the Allens' house sold for $3.6 million in August.

"People spend three to $4 million for a house, knock it flat, and build a big new house on the lot," she said.

Allen still works part-time for the East Palo Alto school district doing tech support, but her husband, a former patent attorney, is fully retired.

If Allen's husband, who has Parkinson's disease, develops dementia and she can no longer take care of him, they plan to move into assisted living in Utah, where two of their kids live and where long-term care is cheaper than in California. But they hope to stay in their neighborhood, where they have strong ties with neighbors and friends, for as long as they can.

"Our support system, our friends — we have a really strong church community here," Allen said. "We really want to stay here."

• Accessory Dwelling Units (ADUs) have become a popular alternative to traditional homes and apartments.
• Three people who built and moved into ADUs shared with BI how they improved their lives.
• One person said moving into an ADU "was the best decision we ever made."

For newlyweds Aislyn and Ali Benjamin, purchasing a traditional home in Danville, California — a small city just over an hour's drive east of San Francisco — wasn't financially feasible.

It's easy to see why. Data from Realtor.com shows that the area's median home sale price is about $1.9 million as of December.

The Benjamins weren't keen on moving too far from Danville in search of a more affordable home, nor were they interested in renting long-term. So, they opted for another solution: building an accessory dwelling unit, or ADU, in their parent's backyard.

Today, they live in a 1,200-square-foot, three-bedroom, two-bathroom ADU in San Ramon, a city neighboring Danville. The home cost $500,000 to build, which the couple paid with their parents' help.

"This was the best decision we ever made," Ali Benjamin told Business Insider. "It allowed us to save so much money and live where we wanted."

ADUs are an affordable entry to homeownership

ADUs are compact housing units, typically 150 to 1,200 square feet, depending on location. On average, they cost between $100,000 and $300,000 to design and build, though additional expenses — such as site preparation, inspections, utility hookups, and permits — can drive up the total cost.

Thanks to their affordability and minimal land requirements, ADUs have become a popular alternative to traditional homes and apartments, particularly for first-time homeowners like the Benjamins, who navigated high home prices, mortgage rates, and a shortage of available homes.

To boost the supply of affordable housing, several states, including California, New York, and Vermont, have supported ADU construction by offering grant programs to help homeowners finance the building process.

In California, where most backyard homes are built, the state's Accessory Dwelling Unit Grant Program has provided grants of up to $40,000 to qualified homeowners — it's been instrumental in driving the growth of ADUs across the Golden State.

According to an April report from the Urban Institute, ADUs accounted for just 8% of permits and 5% of completions in California in 2018. By 2022, however, they represented 18% of total permits and production.

A couple built an ADU to give their adult son more independence

People build ADUs for various reasons, including generating income by renting out the ADU or their main home. Others build ADUs to create comfortable, semi-independent living spaces for aging parents or adult children who may need assistance or support.

Take Todd Kuchta, a 58-year-old engineer who built an ADU in his Napa, California, backyard for his 26-year-old son, Jacob, who has autism.

As Kuchta's son grew older, he desired more independence from his parents but still needed their help with daily tasks like cleaning, taking medication, and preparing meals.

Unable to afford a larger home or an assisted living facility for their son, Kuchta and his wife hired Bay Area-based ADU builder Villa to construct a 480-square-foot, one-bedroom, one-bathroom tiny home on their property.

The ADU cost over $248,000 to build. The Kuchtas received financing through Napa County's Affordable ADU program, which provided a $63,000 forgivable loan. They also secured a $160,000 loan from a credit union as a second mortgage.

The new living arrangement has mutually benefited the Kucthas and their son.

"Jacob really enjoys living on his own — he's thriving," Kuchta told BI.

He added that he and his wife's "stress has significantly decreased, and they have peace of mind knowing they can still provide the emotional support he needs."

A woman built an ADU in her backyard to age in place

The growing trend of multiple generations living together, either under the same roof or on the same property, has fueled the rise of "granny pods" — small outbuildings designed to provide support while allowing older adults to age in place and maintain their independence.

Struggling with the stairs in her two-story home, 72-year-old Wilder-Abrams moved into a 560-square-foot, one-bedroom, one-bathroom granny pod in her backyard in 2022.

Meanwhile, her 34-year-old daughter moved into the home she had lived in for 35 years — a 2,000-square-foot, three-bedroom, two-bathroom home — with her 3-year-old daughter.

"I was ready to downsize and have a smaller place to live and take care of," Wilder-Abrams told BI. "The home is in an urban area, so there are a lot of possibilities for my daughter, too."

The ADU cost $350,000 to build. Wilder-Abrams secured a second mortgage on her home to finance the construction, as the original mortgage had been paid off years ago. Her daughter now pays $1,500 monthly rent, covering the new mortgage payment.

Beyond the financial benefits, home swapping has provided Wilder-Abrams with valuable physical and emotional support. She said having her daughter nearby was crucial to her recovery after knee surgery last year.

"The first few days, she stayed with me to change the ice packs regularly," Wilder-Abrams said. "It was so convenient for both of us."

• New York City is on the verge of legalizing accessory dwelling units in much of the city.
• One expert estimates the city's housing reform will create 20,000 such secondary units.
• The effort is part of the mayor's "City of Yes" housing plan, designed to boost the supply of homes.

In a city where reasonably priced apartments are difficult to find, a new type of affordable home might soon be legal.

As part of Mayor Eric Adams' "City of Yes" housing package — an effort to create more housing of all kinds by loosening regulations — New York City is on the verge of legalizing accessory dwelling units, or ADUs, in certain neighborhoods across the five boroughs. The policy reform is expected to result in thousands of backyard tiny homes and converted garages, basements, and attics.

Housing policy experts view the shift as a first step in expanding a neighborhood's capacity for additional residents and a way to create more affordable housing, particularly in neighborhoods dominated by single-family homes.

These homes are an increasingly popular way to boost density without building apartment towers, adding new housing options and income opportunities for homeowners who choose to rent out their extra units. More than a dozen states across the country have legalized ADUs in recent years, and New York State greenlit the secondary units in 2022, although New York City has restricted them.

"ADUs are a proven tool in cities across the country to support working families with extra space, additional income, and the opportunity to age in place," Dan Garodnick, director of the New York City Department of City Planning, told Business Insider in a statement.

In a key vote last week, two city council subcommittees agreed to a modified version of the mayor's plan that's expected to pave the way for about 20,000 ADUs over 15 years — about half as many as would have been built under the original plan, according to Marcel Negret, director of land use planning at the Regional Plan Association, a pro-housing nonprofit focused on the tri-state area. City of Yes is expected to pass the full council on December 5.

A nationwide push for ADUs

New York is following in the footsteps of cities like Los Angeles and Seattle that view ADUs — also known as "granny flats" — as low-hanging fruit in the quest for more affordable housing. ADU construction has surged in California, where accessory units made up nearly 20% of new homes built last year, and tend to offer more affordable rental units.

Nolan Gray, research director at California YIMBY, called ADU legalization "the beachhead for broader reform" of housing policy because backyard homes tend to be popular with homeowners who've otherwise resisted new housing in their neighborhoods.

"You start to de-normalize this idea that 75% to 90% of the typical American city is going to be off limits to any form of multifamily," he said.

Last year, New York City rolled out a pilot program that awarded 15 homeowners with up to nearly $400,000 in funding per household to build an extra dwelling in their backyard, basement, or attic. The city has since expanded that program, but it only applies to lots that are already zoned to accommodate another unit.

As part of the policy reforms, the City plans to adjust a slew of zoning laws and building codes to allow for ADUs. It will also create a "one stop shop" website to guide homeowners through the construction process, including a set of pre-approved designs, the city said.

"What we're doing, essentially, is just ensuring that every layer of government that could potentially have some sway over whether you can build an ADU is actually allowing you to do so," Casey Berkovitz, press secretary for the Department of City Planning, told Business Insider.

Some outer-borough councilmembers are skeptical

Outer-borough members who represent some of the least dense neighborhoods in the city — where ADUs are potentially most feasible — are among the most vocal opponents of City of Yes. Councilmember Vicky Paladino, a Republican who represents Northeast Queens, has called the mayor's plan "a calculated effort to destroy the character of our districts." Another Republican council member opposed to City of Yes derided ADUs as backyard "treehouses" that would depress home values.

While the city's original plan was estimated to create up to 40,000 ADUs over 15 years — as part of a total of more than 100,000 new units — the councilmembers imposed some additional restrictions that will shrink that number, including blocking them in neighborhoods that only allow rowhouses or single-family detached homes.

Despite the council's restrictions, there are many neighborhoods that aren't exclusively zoned for one- and two-family homes, but are still dominated by them. Such areas could be prime targets for backyard units, garage conversions, and other types of accessory units, Negret said.

"There are many other locations that still have single-family parcels that are not zoned under those categories where you could probably see ADUs popping up," Negret said.

Are you a New Yorker interested in building an ADU? Are you a homeowner with an ADU? Reach out to this reporter at [email protected].