Ethan Arnheim transformed a 360-square-foot storage unit behind his home into a rental apartment. (Katherine Frey/The Washington Post)

Haiti, Iraq, Kazakhstan, Kenya, Sri Lanka and Ukraine are just some of the places where Ethan Arnheim, 35, has worked as an adviser with the United States Agency for International Development.

Souvenirs from his trips are displayed throughout his home in the District’s LeDroit Park neighborhood. Showcased on the main level are large, colorful artworks, collected during a 20-month stay in Pakistan, that were made to decorate trucks.

Arnheim’s travel interests extend to hosting out-of-town visitors. Three small dwellings on his property — a basement apartment, a carriage house and a converted storage unit — are listed on Airbnb and have attracted a steady stream of business travelers and tourists.

“Airbnb is a great way to get visitors into LeDroit Park, which is a very special neighborhood they might not otherwise visit,” says Arnheim, who helped plan the heritage trail signs in the neighborhood. “I like participating in the sharing economy and have met some really remarkable tenants.”

Renters have included actors from the Kennedy Center production of “Book of Mormon,” members of the rock band Haim playing the 9:30 Club and an Uzbek political dissident who testified before Congress on civil rights in Central Asia. Another guest was Columbia University law professor Tim Wu who coined the term “net neutrality,” the idea that Internet operators shouldn’t block or favor certain content.

Arnheim bought his 1890s brick row house in 2010 for $595,000 with the idea of renovating and leasing its lower level and the carriage house at the rear of the property to help pay the mortgage.

In 2011, he worked with a building contractor to renovate the basement into a one-bedroom, one-bathroom apartment while preserving its historic charm. The living area features wainscoting and an exposed brick wall with a fireplace.

Space for the bedroom was carved out by removing a staircase connecting the home’s main level to the floor below. Now, Arnheim’s home and adjoining rental unit are completely separate, and tenants have use of entrances at the front and back directly opening to the outdoors.

The two-level brick carriage house, separated from the main house by a deck and a patio, had been remodeled by a previous owner. Arnheim upgraded the one-bedroom unit further by installing butcher-block kitchen countertops and a washer and dryer on the second level, which is reached from a spiral staircase. “I feel like in-unit laundry facilities are a requirement for any complete rental in D.C. as there are so few laundromats in the city,” he says.

In May, Arnheim completed a two-year renovation of a one-story structure attached to the carriage house on the alley side. He converted this dilapidated, tiny space, formerly used by a metalworker to store supplies, into another rental unit, and did most of the remodeling himself to save money.

“It was in bad shape. There were massive steel doors, no plumbing or electrical, and bricks that hadn’t been repointed in many decades,” he says.

Arnheim began the renovation by tearing out the old concrete floors, inserting four skylights into the roof and adding clerestory windows to the entrance side of the building. The original steel around the entrance was replaced with a rustic wooden door, purchased from Southern Sales Services, a building supply company in Baltimore, and new brickwork to create a more welcoming facade.

Above the new door, a transom window fashioned by Terraza Stained Glass of Baltimore spells out the address and name of the small dwelling, which Arnheim dubbed “ERA” after his initials.

The stained glass transom above the door incorporates the owner’s initials, the address and the D.C. flag. (Katherine Frey/The Washington Post)

Inside the 360-square-foot space, the original brick walls were repointed and acid-washed to remove remnants of dingy, gray paint. “I like an urban, modern aesthetic, slightly industrial, which is why I kept a lot of the brick exposed,” Arnheim says.

The bathroom and kitchen were built on one end of the space, with a sleeping loft extended over the bathroom, and taller areas reserved for living and dining. Bamboo floors from Lumber Liquidators extend through the living, dining and kitchen areas to unify the space.

The simple layout, Arnheim says, was inspired by a friend’s small loft in Nice, France. “The arrangement of spaces was similar and showed me that I had the room in the storage unit to make a fully livable apartment,” he says.

In the kitchen, Arnheim cut costs by installing cabinets, countertops, a corner sink and a microwave, all from Ikea, and a ceramic backsplash from the Tile Store in Rockville. He clad the bathroom and shower with dark tile resembling marble, and tucked a combination washer-dryer under the vanity for laundry.

To reach the bed in the sleeping loft, he originally installed a library ladder. “It wasn’t sturdy enough and I wanted something more graceful than such a utilitarian design,” he says.

An Internet search led the homeowner to commission Hyattsville metalsmith Jesse Robinson to design a more sculptural connection. “What set Jesse apart was that he talked animatedly about visiting the Corcoran to see the [Rochester, N.Y., metal sculptor] Albert Paley exhibit and cited Paley as an inspiration,” Arnheim says. “That gave me the assurance that he had an appreciation for aesthetics and would not just provide a piece that was merely functional.”

Robinson designed curving metal supports spanned by generous wooden treads and a landing at the top that make the climb to the bed easier. Diagonal metal struts along the sides of the ladder reinforce the industrial feeling of the interior.

Separate areas for the living room, kitchen, office and loft make the 360-square-foot space feel bigger. (Katherine Frey/The Washington Post)

To allow for more headroom in the sleeping loft, Arnheim purchased a 6-inch-thick, queen-sized mattress rather than one of standard depth, which can reach more than a foot for a pillow-top style. He erected glass panels at the side of the loft for safety and mounted the TV in the living space so it can be seen from the bed.

The renovation cost about $50,000 and took about two years because of delays in shipments of lighting and hardware, and Arnheim’s travel schedule. Recessed LED lighting was purchased from Craigslist but required Ethernet cabling and a special dimmer to control the lights so they would change color to shift the mood in the space. Arnheim says it took three electricians to figure out the lighting and the exposed conduit encircling the brick walls of the unit.

In 2014, before the interior was completed, Arnheim lived in the space for a few months, while renting out his row house. “Living there in a partially finished state helped me iron out some of the remaining kinks.”

One of those kinks was moisture seeping through the brick wall near the desk next to the bathroom where the floor is set below the ground. “I’d repointed the exterior, but hadn’t dug down to the foundation,” Arnheim says. “This led to a bit of mold in the area where there is the least light.” So after unearthing the foundation, he coated the exterior with a moisture-resistant paint and added a ductless humidifier on the inside for good measure.

Other fine-tuning included applying a frosted coating on the bathroom’s glass door after visiting friends complained they didn’t have enough privacy. A planter was installed in one of the windows to block the glare from a neighbor’s security lights.

By spring of this year, the ERA apartment was ready for its first tenant. Arnheim booked his first Airbnb guests, an Israeli couple, and has since had steady bookings.

Of his three rental units, the homeowner admits his favorite is the ERA since he did most of the renovating himself. He attributes his pride to the “Ikea effect — consumers feel a greater attachment when they’ve been more involved with the assembly of something.”

Arnheim says the compact, open-plan loft “is more my style” than the ornamented rooms of his Victorian row house.

“I would live in the ERA, but it would require some serious downsizing.”

Deborah K. Dietsch is a freelance writer.