sentences:  As of 2017, spectators can also observe play at Show Courts 2 and 3, which have capacities of 3,000 each, as well as at Courts 7–15, 19 and 20 from small accessible viewing positions.Construction of a new 5,000 seat capacity stadium will start in 2019 as part of a $271 million redevelopment of the precinct.Since 2008, all of the courts used during the Australian Open are hard courts with Plexicushion acrylic surfaces (though Melbourne Park does have 8 clay courts not used for the tournament).