The blaze occurred at the Den Breejen shipyard in Holland where the vessel is being built.
Sister line Scenic also had a ship under construction nearby but it was quickly moved and it only suffered some paintwork damage.
“At 12:30 am (UTC+1:00) Sunday morning, the owner of the Den Breejen Shipyard was alerted to a fire on the Emerald Belle,” said Glen Moroney, chairman of the Scenic Group, owners of the Emerald Waterways line.
“Despite the efforts of firefighters, who were quickly at the scene, the damage is significant. We are grateful and relieved that nobody was onboard at the time and most importantly, there were no injuries to any shipyard worker or firefighters to our knowledge.”
The cause of the fire is yet to be identified.
Emerald Belle was due to launch April but this may now be delayed.
The line’s operations and reservations team are reviewing all bookings to see how best to accommodate guests on similar departures on other Emerald ships or possibly on her sister company, Scenic.