MONTPELIER — The Federal Emergency Management Agency and state of Vermont had hoped to complete funding arrangements for the rebuilding of the Waterbury state office complex by the end of February but FEMA now says more time is needed.

The two sides are working to determine how much FEMA will contribute to the cost of reconstructing the complex, most of which was flooded and made unusable by Tropical Storm Irene in August 2011.

The state has designed a project that would demolish some of the existing structures, repair others and build new structures above the flood level.

The project is expected to cost $124.7 million. The state’s insurance company will also contribute.

FEMA said Wednesday that it is working to get the most funding possible to allow the state to start rebuilding.