A look inside the £260m New Tate Modern that opens this weekend

The New Tate modern will open to the public this Friday. The Switch House, designed by the architects of the original building conversion Herzog and de Meuron, increases the size of Tate modern by 60% and provides ten storeys of spaces for art and learning.

The opening will be marked with a weekend of free live performances, new commissions and special events. For the following three weeks, live art will animate the spaces with works including Tania Brugrera’s police on horseback and Tino Sehgal’s gallery attendants bursting into song.

“When we were in this building 20 years ago it was a derelict power station. Today it is the most visited art institution in the world,” said Tate director Nick Serota at the launch this morning. “When we opened Tate modern we expected 2 million visitors a year. Now we welcome over 5 million.” The original Tate building has been credited with transforming London’s South Bank, taking a decommissioned power station and turning it into a world renowned gallery.

“Tate Modern has changed London since 2000. The impact it has had on urban design and the development of the South Bank and Southwark has been as substantial as its influence on the city’s artistic, cultural and social life,” said architect Jacques Herzog. “The new extension will add another decisive dimension to the architecture and environment of this quarter and beyond. An addition to the existing building is always very difficult, even problematic: some people will like the new part better, others will prefer the old part, some might say that the new extension was not necessary, others are convinced of the opposite. We wanted to anticipate such controversial views. Our aim was to create a building conglomerate which appears as one thing, not as phase one and phase two.”

The new building provides generous gallery spaces that can be reconfigured to accommodate art of many scales. The exterior is clad in brick that covers the faceted concrete structure that is visible from the interior. “Our aim was to create an architecture that allows for flexibility, improvisation, adaptation and change,” said Ascan Mergenthaler, senior partner at Herzog and de Meuron. “We conceived the new Switch House as a lively civic space including internal streets and plazas framed by a concrete skeleton and enveloped with a brick veil, knitting it back together with the Boiler House to complete and form the new Tate Modern.”

London mayor Sadiq Khan said at the opening: “The Tate modern is a pioneer. Where most of us saw a derelict power station, Nick Serota saw an art gallery. For too long culture has been a nice to have. I have made culture one of the big things I want to define my time as mayor. Right up there with housing environment and transport.”

The £260m building opens to the public on Friday.