LONDON — The crypt and parts of Notre-Dame Cathedral’s plaza are expected to reopen to the public in the spring, Paris officials said this week — almost a year after the landmark 850-year-old building was mauled by a fire that devoured its roof, weakened its structure and sent shock waves through France and beyond.

The beloved cathedral, the park behind it and the plaza nearby have remained closed amid fears of lead contamination from the damaged church roof and spire. Dozens of workers have been repairing the building that President Emmanuel Macron vowed at the time of the blaze would reopen within five years.

This week, Paris’s deputy mayor, Emmanuel Grégoire, said he hoped that parts of the square in front of the cathedral would become accessible again to the public in the first half of the year “if everything goes OK.”

Mr. Grégoire told a group of lawmakers that workers would first have to remove lead traces from the site, since levels there and in the cathedral’s rubble remain a cause for significant concern.