Shed those preconceptions and you will see it’s art

It looks like a slightly rundown shed — because that's what it is. But as the last unfinished work of one of art's forgotten stars, the Merz Barn is to be recreated at the Royal Academy as a centrepiece of a major new show.

The installation is by German painter and master of collage Kurt Schwitters, who had a huge effect on Brit Pop artists Sir Peter Blake and Richard Hamilton.

Schwitters, who escaped the Nazis but was interned on arrival in Britain during the war, worked on the Cumbrian farm shed in 1947, transforming the interior with a series of wall artworks.

Cumbrian dry stone wallers will make a replica of the crumbling original in the Academy's courtyard in Piccadilly for Modern British Sculpture, the first exhibition in three decades to examine British sculpture in the 20th century.

The exhibition, from January 22 until April 7 next year, will also include works by Jacob Epstein, Henry Moore, Barbara Hepworth, Anthony Caro, Julian Opie and a 1991 Damien Hirst piece, called Let's Eat Outdoors Today, that has never previously been displayed.

Schwitters died at 60 in 1948, the barn project unfinished. Richard Hamilton rescued the surviving works in 1965.

Tate Britain director Penelope Curtis, co-curating the exhibition, contrasted Schwitters's isolation with the international acclaim for Moore and Hepworth in the same period. She hopes the barn will "make people think about where artists make work and who sees it".