Architecture for Humanity, a San Francisco nonprofit that was known for its disaster- rebuilding efforts around the world, has closed.

With no formal announcement at the time, all staff was laid off Jan. 1 by the board, and the nonprofit shut its office near Union Square.

The abrupt demise followed a year of retooling by the organization that at its peak had more than 60 chapters and in 2008 received a National Design Award from the Cooper-Hewitt National Design Museum “for its commitment to bringing sustainable architecture to global communities in need,” such as the Gulf Coast in the aftermath of Hurricane Katrina.

Local observers say the organization’s problem was one that’s inherent to socially ambitious nonprofits — finding ways to keep interest and funding coming when the newness of its mission wears off.

“The travesty isn’t that the organization went over budget serving communities around the world,” said Margie O’Driscoll, former executive director of the San Francisco chapter of the American Institute of Architects. She joined the staff just weeks before the doors were locked. “It is that humanitarian design isn’t considered a fundamental right. And that today, in San Francisco, it is easier to find funding for an app than to fund an organization which transforms lives in places most Americans don’t know exist.

One longtime board member made a similar point more diplomatically.

“The board tried very hard to figure out how to right the organization, and we were out there looking for angels, but the money wasn’t there to support it,” said Clark Manus of the local firm Heller Manus Architects. “It’s not that the mission and need wasn’t clear, or that the staff wasn’t dedicated.”