| Every year more expensive and complicated sports | | | | pitch to grow. Wimbledon famously added a roof to |
| arenas are constructed and even some of the | | | | its centre court, after several tournaments were |
| world's newest and largest sports stadia are being | | | | interrupted by rain and now there is hardly a major |
| built with the option of turning them into indoor | | | | stadium design process that doesn't at least consider |
| facilities. | | | | including a roof. |
| The new Wembley Stadium in London, the most | | | | In the US the redevelopment of the Dallas Cowboys |
| expensive ever built, does have a sliding roof which, | | | | NFL stadium will be the most expensive NFL stadium |
| although it cannot completely close, does afford | | | | ever built when it is completed in 2009. It will have a |
| protection from the weather for fans while still being | | | | 660,000 square foot retractable roof and will have a |
| able to retract and provide the conditions for the | | | | capacity of 100,000. |