Mr. Maltzan stumbled into the role of socially conscious architect. He arrived in Los Angeles in 1988 and was soon working for Frank Gehry, then still a cult figure for young architects looking for a way out of the malaise of postmodernism. In 1993, while at work on the early stages of the Walt Disney Concert Hall design, Mr. Maltzan was approached by Irwin Jaeger, a businessman, and Bob Bates, an artist, to look at a garbage-strewn lot at the edge of Skid Row where they were planning to build a home for Inner City Arts, an after-school program.

Image Inside the Carver Apartments is a cylindrical space in which sheet-metal fins climb its full height. Credit... Iwan Baan

The project became Mr. Maltzan’s first solo commission. A complex of studio spaces clustered around landscaped courtyards, its sculptured white stucco buildings and raw interiors evoked the lyrical architectural forms of Alvaro Siza as well as the sculptural compositions of Mr. Gehry’s work, suggesting a young architect easing into his own voice.

It also demonstrated an unusual sensitivity for those who taught and worked there. The comforting scale of the gardens and studios, animated by light funneling through big skylights and windows set at the eye level of a small child, imbue these spaces with a warmth that is rare in low-budget construction.

The project attracted the attention of the Skid Row Housing Trust, an organization dedicated to providing permanent homes for the most vulnerable members of the downtown homeless population  people with a combination of disabling conditions like drug addictions, mental illnesses and physical disabilities who had drifted in and out of shelters for years.

Mr. Maltzan’s first building for the trust, the Rainbow apartment complex, is surrounded by Skid Row’s sprawling encampments. To shelter the tenants from the nearby misery, Mr. Maltzan oriented its 87 apartments around a big ceremonial staircase and an outdoor courtyard. From a shared top-floor terrace, tenants look over toward the glittering towers of the business district a few blocks away, which in this neighborhood can sometimes seem an unreachable oasis of prosperity and calm. The project, completed in 2006, offered a sharp contrast to the soul-crushing atmosphere of more typical homeless shelters, from which many of its tenants had been plucked.