The Grand Slams have long been preoccupied with becoming grander slams, and despite all the earth moving in the past, the trend shows no sign of abating.

Wimbledon has a new Court Two and will open (and close) the once-unthinkable translucent roof over Centre Court this summer as it rings in a new era at the All England Club free of rainy-day diversions like Cliff Richey singalongs and replays of great, dry matches past on the BBC.

The U.S. Open, encouraged by new technologies, continues to investigate building a roof of its own over cavernous Arthur Ashe Stadium to avoid a repeat of last year's men's final on a Monday.

Meanwhile, Australian Open organizers, eager to secure the tournament's future in Melbourne, have announced plans to redevelop the grounds at Melbourne Park by 2016, with estimates of the cost running as high as 500 million Australian dollars, or $320 million. The wish list includes a refurbished Rod Laver Arena, a vast piazza-style public square and a roof over the tournament's third showcourt: Margaret Court Arena.

But the most unconventional plan currently being explored is at the French Open, where the French tennis federation and the city of Paris are seriously considering the building of a new stadium with a retractable roof in the midst of the Porte d'Auteuil, the vast and bustling intersection that lies well outside the tournament's existing grounds.

The proposed site, currently occupied by a soccer stadium, is 500 meters away from the nearest entrance to Roland Garros stadium, separated from the world's most famous clay courts by large, ornamental public gardens and, for now, plenty of vehicular traffic.

Creating a plausible, aesthetically pleasing way of linking the new stadium and the old is an architectural challenge to say the least. In December, four architects were selected to submit formal proposals out of 91 candidates. A winner is expected to be chosen by May, and one of the four postulants is Renzo Piano, the high-profile Italian who has already helped design one Parisian landmark: the avant-garde Centre Georges Pompidou.

There has been talk of an elevated pedestrian passageway linking the two stadiums, but 500 meters—more than five football fields—is a lot of passageway.

"It's obvious that it's a configuration that is not easy in terms of organizing the tournament," says Gilbert Ysern, the French Open's new director. "But it's a question of getting the right ideas and executing them."

Roland Garros's new stadium would have been in a much more convenient spot if Paris had managed to win the right to stage the 2012 Summer Olympics. The plan, part of the bid proposal and pre-approved by the French government, was to build inside the Bois de Boulogne, which is located across the street from the existing facility. But London ended up upsetting Paris by four votes, and Wimbledon, not Roland Garros, will now stage the tennis competition at the next Olympics.

Without an Olympics to justify an exception, Paris authorities have refused to consider building in the Bois, a vast stretch of green on the western edge of the city which is a strictly protected site.

But Roland Garros officials, including former French tennis federation present Christian Bimes, have long argued that the tournament needs more space to keep up with the other three Grand Slam tournaments. Its grounds—less than 20 acres—are by far the smallest of the elite group. Its peer group's land holdings are all more than twice that size, with the U.S. Open at 46.4 acres.

Anyone who has attempted to work their way through the masses on the outside courts at Roland Garros during the first week in recent years can only agree with the French assessment. True, the French could have alleviated some of the congestion by selling fewer grounds passes, but then such a move, however intelligent, would have taken away some of their leverage for change. Ysern insists that though Bimes is no longer president of the French federation, the project remains a high priority. And it is all the more a priority because Madrid has a new combined men's and women's claycourt tournament in May with a glittering, cutting-edge facility called La Caja Magica (the Magic Box) that features a massive arena with three show courts that all have their own independent retractable roofs.

"This project will not stop with the departure of Christian Bimes," Ysern says. "These days, to not have the possibility to cover the center court in case of rain is a real handicap, even on clay. That's the first thing we have to resolve, and the second thing is this long-standing issue of room on the grounds. We need space for everything: the players and their entourages, the press and the public. There are more and more people who want to come who can't."

Clearly, there is some concern in Paris that those people may end up flying to Madrid instead.

Christopher Clarey is the chief sports correspondent for the International Herald Tribune and a contributing editor at TENNIS magazine.