More than 30 people attended a public meeting to see early outline plans for the transformation which will link the 18th century Grade 2* building with the Piece Hall via a copper and glass atrium.

A new 100-seat theatre, public sun terrace and continental cafe-bar with art gallery would also be created, the meeting was told. They would be linked by a huge triangular foyer.

Robin Sutcliffe, the retired chairman of the Square Chapel Arts Centre Trust, said: "This place has grown so much over the years it's amazing and this is a new exciting journey we are embarking on.

"It will be the first step of what we hope will turn the whole area back into the heart of Halifax."

And one Piece Hall trader said: "We've been waiting 27 years for someone to do something which will bring people here. Now let's get on and do it."

The development would include knocking through the south wall of the Piece Hall to create a new entrance into the newly expanded Square Chapel.

Funding is expected to come from Yorkshire Forward, Arts Council Yorkshire and Calderdale Council, which has already given its backing to the project.

But not everyone was convinced by the early plans by architects Evans Vettori.

Ian Parker, who regularly volunteers at the Square Chapel, said: "This is an intrusive development to my eye.

"If the Square Chapel needs to expand why not look for a new site instead of imposing it on these two historic buildings which it would not suit."

Another public meeting to discuss proposals will be held at the Square Chapel on Thursday January 15 at 6pm.