This has been revealed by Coun Rob Waltham, who is the leader of North Lincolnshire Council, which owns and operates the building in the Market Place.
The Buttercross has the award-winning Tourist Information Centre on the ground floor, an impressive function room above and the distinctive clock tower on top of that.
Coun Waltham told the Annual Town Meeting that work started on constructing the building during 1817.
He also mentioned plans for a book shop at the Buttercross.
NF ADDS: The general view is that the Buttercross was not completed or opened in 1817.
Exactly when the celebrations will be held have yet to be announced by North Lincolnshire Council.
Brigg Blog recently flagged up the fact that the plaque above the entry door, marking Lady Diana's visit in the 1980s, needs a spot of attention and we are sure this will be attended to in the near future - well before the celebrations begin for the grade two listed structure which housed the offices of Brigg Urban District Council for many years.