"I hope we'll finish in time. We still have a couple windows to add, small columns and carvings," he told AFP Friday at his workshop.
"I hope the cradle will be put in the newborn baby's room," Bergier added.
For the April 2011 royal wedding, Bergier's workshop was commissioned to make several pieces of furniture for a hotel in Stafford where Kate Middleton's family stayed.
But the cradle was intended as a gift for the royal couple, Bergier said.
For the design, he drew his inspiration from 15th-century Gothic cathedrals. "A cradle for the heir to the British throne can't be made in a common style," he explained.
The child will be third in line to the British throne after Charles and William.