The complex renovation project on the 18th century building is now due to start late next year with the help of a Heritage Lottery Fund grant of £7m.
Piece Hall is an important part of Halifax’s history and was built to house prosperous cloth traders some 230 years ago.
The Georgian building is one of only two surviving cloth halls in the whole of Europe and has had a variety of uses over 230 years.
Work involves punching a new ‘fourth’ entrance through the exterior wall of the historic building and transforming the huge courtyard at its heart into a bustling town square.
The upper level of the landmark building boasts more than 300 rooms behind arcades and columns that will be turned into business units. The buildings middle floor has been earmarked for high quality retail use.
Edinburgh-based LDN Architects designed the scheme, which will also see a four-storey extension to the building to be used for commercial purposes including restaurants and cafe.