Two years after opening to the public, The Hepworth Wakefield art gallery in West Yorkshire has announced a significant development as the ground floor of the Caddies Wainwright Mill has been transformed into a new contemporary art space.

The gallery has attracted more than 850,000 visitors to date - more than five times the original target.

The £35m (US$52m, €40.9m) museum contains works by sculptor Barbara Hepworth and a series of changing displays of modern art.

"We have created an inspirational new space in a historic building that will compliment and enhance what we currently offer as the wider site develops here," said Simon Walis, Director of The Hepworth Wakefield. "This new development enhances the regeneration of the waterfront by animating these exceptional historic mill buildings."

The new space adds about 6,500sq ft (600sq m) of floor space.

The exhibition will open later this Summer and the first artwork to be displayed will be by 2009 Turner Prize nominee, Roger Hiorns.