Sunlight fills every corridor, the exit visible even from the opposite end of the apartment building.

Its 60 bedrooms have no doors to shut, but, instead, window-sized wall cutouts to see through to the living room. And the “safe courtyard,” filled with deep-pink rose bushes and shade umbrellas, is open to the sky yet fenced off to prevent outside entry from Federal Boulevard.

The design is unique in Colorado and rare nationally, a “trauma-informed” apartment building that soon will house people who for years have lived on Denver’s streets, in and out of jail, detox and emergency rooms. There are no crevices, nothing that resembles a dark alley or shadowy stairwell.

“These are the folks who are really resistant to treatment. They didn’t sign up for it,” said Joann Toney, director of clinical housing services for the Mental Health Center of Denver which will open Sanderson Apartments to its first residents next week.

Residents didn’t ask to live at Sanderson. They were chosen by researchers who pored through Denver Police data looking for the city’s persistently homeless and frequently arrested, men and women who are marked as “transient” and have rotated in and out of jail mostly for so-called “homeless” crimes — such as illegal camping, trespassing or public intoxication.

The initial list, compiled by Urban Institute in Washington, D.C., included 4,000 names.

The mental health center received the names, birthdates and recent mugshots of 87 people; the Colorado Coalition for the Homeless received 187, chosen randomly from the 4,000.

The agencies’ task was to find those people on the streets of Denver, either by contacting emergency shelters or walking along river paths, homeless camps and in downtown parks. One man known previously to outreach workers was found in a field behind a 7-Eleven.

After several months, the two agencies have found 153 people. Many are now housed in one of the Coalition for the Homeless’ 19 buildings, and dozens more will move into Sanderson Apartments, at Federal Boulevard and Iowa Street in southwest Denver, in the coming weeks.

Researchers will track their progress and compare it to a control group made up of people identified through the study but not selected for housing.

Many of the people found suffer from mental illness and substance abuse — and, in many cases, post-traumatic stress disorder after living for years on the streets. “Our purpose is to help them find recovery in whatever way that means to them,” said Takisha Keesee, the mental health center’s program manager for the team tasked with finding them.

The project’s funding is almost as different as Sanderson’s trauma-informed architecture. About $8.6 million in funding comes from the “Denver social impact bond,” in which private companies and philanthropists loaned the money to the mental health center and the homeless coalition to spend as rent subsidies and treatment for residents.

The city pays the money back if the program succeeds in providing stabilized housing and reducing public costs through decreased arrests, jail time, and detox and emergency-room visits, said Tyler Jaeckel, government innovations fellow for the city.

Denver taxpayers spend an estimated $7 million each year to cover 14,000 days in jail, 2,200 detox visits, 1,500 arrests and 500 emergency-room visits for 250 chronically homeless people — the number expected to receive housing through the program.

Mayor Michael Hancock, who attended Thursday’s ceremonial preview of the building and then helped open a 100-bed Catholic Charities emergency women’s shelter in northeast Denver, noted that Scripture teaches that the poor are among us for a purpose. “They are meant to teach a lesson in compassion and humility,” he said. “As long as I am mayor, we will be a city of compassion.”

Each night in Denver, he said, 3,300 people are “without a home,” many of them “stuck in a cycle of going from the streets to jail to detox to the emergency room.”

“It’s a cycle,” he said, “that must be broken.”

Sanderson Apartments is the latest in the city’s “housing first” model, meaning the first step in treatment of mental illness or drug abuse is housing. “It’s really hard to get well if you don’t have a place to live,” said Carl Clark, president of the mental health center.

Each apartment unit comes with bed linens and towels, bug-resistant mattresses and furniture, and a television. There are no dishwashers — to cut down on maintenance — because for many residents, “letting our maintenance staff in the unit is very hard,” housing director Toney said.

People who are chronically homeless and have experienced assault, sexual assault or other trauma often remain on the streets because they despise sleeping in the close quarters of emergency shelters, where mats or cots typically are just inches apart. That’s why Sanderson is so airy and filtered with natural light, high ceilings and common areas that have open walls instead of just a doorway.

Bathrooms have doors that lock. A person can lie in bed and look through to their living room, so they can “see if there is anything to worry about,” Toney said.

Apartment unit doorways are on the inside of the building, which is next to Torres Mexican restaurant and a preschool. Hallways start wide and grow more narrow, every apartment doorway visible at once. Oriana Sanchez, the mental health center’s director of real estate, found no other trauma-informed building in the nation.

The building has a safety officer and residential counselors, who are ready to answer questions such as “How do I cook a turkey?” or “How do I deal with my loud neighbor?” When residents are ready for mental-health or substance-abuse treatment, caseworkers will invite them to the mental health center east of downtown.

“We know we can’t get too much into their business too fast,” Toney said.

Unlike many other shelters and housing programs, there are no restrictions regarding drugs and alcohol in private units. Some residents have served prison time. There is no time limit on how long residents can remain in the apartments, and mental health center staff will help those who qualify apply for government housing vouchers, Social Security and disability. Rent will be income-based.

Catholic Charities, meanwhile, opened a 100-bed shelter for women in a renovated building northeast of the city Thursday. Women, who make up one-third of Denver’s homeless population, quickly fill downtown shelters.

After a hot dinner at the Samaritan House downtown, women can board a bus each night to the shelter several miles to the northeast and then return by bus the next morning for breakfast. The location of the shelter, now the largest women-only shelter in Denver, is kept secret because many of the women have lived through domestic violence, said Catholic Charities president Larry Smith.

Women in the emergency shelter can seek a spot in a longer-term housing program, which includes mental health services and help searching for employment.