The £9.25m project to provide a new library and heritage centre in the town centre includes a new east extension and a redesigned courtyard (pictured below).
The Piece Hall and the new Central Library & Archive are scheduled to open in spring 2016.
Graham Construction regional director Gary Hughes said: “The Piece Hall is a historic and much-loved building which is part of the fabric of Halifax. The refurbishment will therefore be extremely sensitive to its heritage.”
The project is being funded by Calderdale Council and a £7m grant from the Heritage Lottery Fund.