The vast majority of the city’s 1,263 school buildings don’t have door alarms, but nearly every principal wants them installed at their school, according to a city report publicized Thursday by City Council members.

The figures followed a building-by-building survey of city schools required by Avonte’s Law, passed after Avonte Oquendo, a 14-year-old with autism, exited unnoticed through a side door at his Queens school in October 2013. His disappearance and death prompted outrage and put pressure on the Department of Education to reassess its student safety protocols.

The law required the department to assess which buildings could use and wanted alarms, as well as what safety training school staff members receive. The city’s report was released at a press conference outside City Hall, where Council members were joined by an unusual coalition of education advocates.

Ninety-seven percent of school buildings requested alarms, although demand was slightly lower (92 percent) among schools that served older students, according to the results of a survey administered between December 2014 and March 2015. Officials said the most schools that did not ask for alarms either already had them or operated in larger facilities, such as college campuses, where other security measures were in place.

The city has already begun to install the alarms, and officials said they expected all buildings to be outfitted by the end of the year at a cost of $5.5 million.

Robert Cornegy, Jr., the Council member who sponsored Avonte’s Law, said the department was not required to begin installing door alarms until this summer, praising the city’s efforts to begin the work early.

“They used their own safety money, which represented a testament to the fact that this was a priority,” Cornegy, Jr. said.

An investigation into Oquendo’s disappearance found no specific wrongdoing, but highlighted a distracted school safety agent and preoccupied paraprofessionals. The report noted that the side door where Oquendo exited had been left ajar, but did not specifically recommend door alarms.

The teachers union and the education department both expressed misgivings about an initial version of the law, which would have required alarms on every door in a building. But representatives from the city, the union, as well as parents with StudentsFirstNY, an advocacy organization that often clashes with the union and criticizes the de Blasio administration over its education policies, all showed up for Thursday’s press conference.

Carmen Alvarez, a vice president for the United Federation of Teachers, said that while the addition of door alarms will provide some measure of safety, better training was needed to prevent a student from ever leaving unnoticed in the first place.

“Remember, the alarm is a measure of last resort,” Alvarez said.