For years, Chris Iverson lived in half of the duplex he owned in Minneapolis' Longfellow neighborhood. When he adopted a child, he moved to St. Louis Park to be closer to family.

"I did the suburban thing for a few years," he said.

But once his daughter graduated from high school, he missed living in an urban neighborhood. "I preferred the city vibe," he said. And he no longer needed a 2,700-square-foot house.

It was time to downsize.

Iverson considered a condo, but didn't want to pay association fees. Luckily he had another option: to build a very small house — an accessory dwelling unit, or ADU — behind his duplex, which he still owned and rented out.

A Google search led Iverson to architect Chris Strom, of Christopher Strom Architects and Second Suite, who has designed various ADUs since the city approved them in 2014.

"Chris had engaged with the city on ADU planning, and he had insight," said Iverson.

Strom's experience working with the city came in handy when they learned that Iverson would need to get his property rezoned.

"The zoning code hadn't caught up to the [ADU] ordinance," said Strom. "The city was figuring it out."

Iverson's lot was ideal for an ADU, according to Strom.

"What makes this site fantastic is that it's a corner lot that faces south on a side street," he said, so the ADU can face the street instead of the rear of the duplex. "It has an identity. It's its own thing."

While some owners want their ADUs to match the existing house, Iverson wanted a completely different look.

"I wanted contemporary," he said. He chose a flat roof to help maximize space inside his dwelling. (ADUs have restrictions on square footage and height.)

Strom designed a 640-square-foot home set on top of a garage, with a second-floor deck of ipé wood.

Inside, the floor plan is open, with the kitchen at one end of the living area and a sofa and chairs at the other.

There's a bedroom, a walk-in closet and a bathroom with a tub/shower and a washer/dryer. There's even a niche off the kitchen designed to accommodate Iverson's upright piano. (No TV. Iverson doesn't have one.)

The flooring is dark espresso-hued Marmoleum, which contrasts with the white walls. "It looks like wood but the lack of seams ties the room together, Strom said.

Iverson likes blue and orange, so those colors were used as vivid accents, including a blue kitchen countertop, blue-stained oak stair treads and blue-and-white tile in the bathroom. An orange sliding door separates the living area from the bedroom.

The small space is light and bright, thanks to skylights and lots of windows, including several slot windows — high-placed horizontal windows that capture slices of light and views.

"They become artwork themselves, framing what's going on in the sky or the trees," said Iverson.

"It's airy — a happy space," said Strom. "An ADU is like a studio apartment, but in a studio, you have one wall with glass, two if you're lucky and have a corner unit.

"In an ADU, you can have windows facing five ways — all four walls and up to the sky. It lives totally different than a studio, even though it's the same size."

One of Iverson's windows is a 6-foot opening with a retractable screen, placed above the kitchen sink and overlooking the street. The window has a bright orange frame, adding a pop of color to the exterior.

"The design is eye-catching," said Iverson. "I would never have envisioned this exterior. It's why design is important as ADUs become more popular. You could put up boxes everywhere, but it's cool to look at cool things."

Attention magnet

The highly visible, modern house definitely stands out in a neighborhood of older homes.

"I was not prepared" for all the attention it attracts, said Iverson.

He's had strangers knock on his door and ask to see inside. Neighbors are interested, too.

"At the grocery store, a guy asked, 'Do you live in that house?' Kids love it. One said, 'You're like a real-life Tony Stark,' " the main character in the movie "Iron Man" who lives in a futuristic house. "They say, 'We want to live in this place.' "

Iverson said living in a compact space takes some adjustment but that it has more pluses than minuses.

"I'm using the space I have," he said. "Nothing is wasted."

His cost of living is lower. He has a wall-mounted heat pump, designed for small spaces, but he rarely has to use it; his heated floors keep his home comfortably warm in winter.

"Cleaning is a lot easier," Iverson said. And he accumulates fewer things because he has fewer places to put them.

"I now have the mind-set when buying something, 'Is it a necessity?' I don't have space for things."

The one downside is that he doesn't have a guest room. So when his 23-year-old daughter comes to town, she stays with Iverson's parents.

As for living literally in his renters' backyard, Iverson prefers it to being miles away.

"I like being close to my tenants," he said. "If anything comes up, I can address it quickly."

Costs, restrictions

ADUs are small, but not as inexpensive as people might assume, said Strom.

"Some people think of an ADU as a tricked-out garage but it's a house with a garage underneath — a two-story home — just small."

Building one similar in size to Iverson's costs about $250,000. "I went a little over," he said, because he chose to splurge on things like the heated floors and the big orange window. Cable railings on the deck and staircase inside also added cost, Strom said.

Iverson doesn't regret his splurges — or anything else about his home.

"There's nothing I would change," he said. "I basically built the condo I wanted here in the city."

He intends to live in it long term, and signed a covenant with the city pledging to do so.

Under current city requirements, "you have to live in your ADU or the other dwelling on the property," said Strom. "Investors can't just build one. A family can do it once, to meet their needs."

That may change, however. Council Member Cam Gordon recently proposed amending the ordinance to eliminate the owner-occupancy requirement.

Iverson spends a lot of time in his little ADU because he works from home, in tech sales. But living and working in one room doesn't feel confining.

When he wants a change of scene, "I can go to Turtle Bread and hang out," he said. "There's no shortage of coffee shops in this neighborhood."