Bronx and city building codes got their first major update in decades when Mayor Michael Bloomberg outlined a new plan Thursday.

The changes reflect lessons learned about emergency evacuations and fire safety after the 2001 World Trade Center attacks. The changes require buildings to have sprinklers, smoke detectors and water reserves to help firefighters fight blazes.

The code revision also calls for impact-resistant elevator shafts and stairwells for high-rise residential and commercial buildings.

Bloomberg says the changes will allow all city buildings to be built to national standards.

The hefty building document will have to be approved by the City Council before it goes into effect.

AP wire reports contributed to this report.