Tate Modern Announces Plans for an Annex NYTimes

Tate Modern, which now says it is the most visited modern-art museum on earth, unveiled plans on Tuesday for a striking $397 million extension intended to be completed in time for the 2012 London Olympics.

The annex, which resembles glass boxes stacked up arbitrarily to form a 220-foot pyramid, has been designed by the Swiss firm Jacques Herzog and Pierre de Meuron, the same architects who in the late 1990’s turned an abandoned power station on the south bank of the Thames, across from St. Paul’s Cathedral, into Tate Modern.

The addition will make the museum comparable in size to the Georges Pompidou Center in Paris and the Museum of Modern Art in New York.

The extraordinary success of Tate Modern since its opening in 2000 explains the need for more space.

“It was designed for 1.8 million people per year,” said Sir Nicholas Serota, who as director of Tate also oversees Tate Britain, Tate Liverpool and Tate St. Ives, “and now we have over four million visitors per year.” The Tate said that figure compares with 2.5 million visitors annually for the Pompidou and 2.7 million for MoMA.

Vicente Todoli, the director of Tate Modern, said that on weekends “we have people looking at people looking at people looking at art — not the best experience.”

The 11-story annex, which will be entered either from a new plaza or through Tate Modern’s vast Turbine Hall, will provide relief from crowding by offering new galleries of different shapes and sizes intended to accommodate installations, videos, film, photography, performance and other nontraditional art forms.

The opportunity to build emerged by good fortune: the French-owned electricity company E.D.F Energy, which in 2000 retained the southern third of the Tate Modern building as a substation, decided to release half of this space as part of its own modernization.

Assigned to the southwestern flank of the site, Tate Modern’s planned annex should give new momentum to the transformation of the south bank of the Thames, a district that was long abandoned and in recent years has benefited from the 20 or so cultural and entertainment institutions that now line the river’s edge, from Westminster to Tower Bridge. These include the Festival Hall, the National Theater and Shakespeare’s Globe Theater.

The novelty in the Tate Modern annex is that it will turn the museum’s face away from the river and toward the borough of Southwark. “The river is the east-west axis,” said Nicholas Stanton, leader of the Southwark Council, “and now we will have a north-south axis, from St. Paul’s Cathedral, across the Millennium Bridge, through Turbine Hall and south into Southwark.”

The museum’s role in urban development is one reason that the London Development Agency has been the first to invest — $12.7 million — in the expansion. And that is all Sir Nicholas has available so far. But while the extension will really cost more or less the same amount as the original conversion of the power station, he seems unperturbed.

“We are in England,” he said with a smile. “No one asks you to do this. We start with a very strong idea and a lot of people who are interested in helping. We don’t start with a war chest. We start with an ambition and a need. If it catches on, we’ll find the funding.”

The timing looks good.

In the late 1990’s, when Tate Modern was given $90 million from national lottery profits for its building conversion project, the Victoria and Albert Museum’s own planned extension was refused such aid, by all accounts because of opposition to Daniel Libeskind’s very modern design.

Since then, public resistance to contemporary architecture has softened. And because Tate Modern is now the strongest symbol of London’s rapid emergence as a cultural capital, it could become a good candidate to receive more lottery funds. As for private contributions, Sir Nicholas said it might be possible to name some galleries after major donors.

For Londoners, though, the principal curiosity will be the annex’s appearance. And here, Mr. Herzog and Mr. De Meuron have chosen not to be shy. In a statement they said that it would be “simpleminded arrogance” for the annex to dominate Tate Modern, but that it would also be “false modesty” to hide it behind the existing building.

Thus, as seen from the river, the top of the pyramid, or ziggurat, as one architecture critic described it, will be visible above the broad facade of the current museum. Viewed from the south, though, the annex will make a far stronger statement, with its thick glass windows and walls suggesting transparency and solidity.

“A lot has still to be defined, and that is on purpose,” Mr. Herzog said. “We are free to make changes up the end. This is a working strategy.”

Still, he and his team have already decided to make use of three large, circular oil tanks that were used by the oil-fired power station until 1961. These will serve as the annex’s basement and even afford room for a new 400-seat auditorium. With light brought into the annex through various openings, a wide staircase sweeping up 10 floors will then provide an internal logic to a building that from the outside can look almost accidental.