 In the 20th century several changes took place , with the Ballroom becoming a cinema , until the Society for the Protection of Ancient Buildings became the owners in 1931 . The building was restored by A Mowbray Green in 1938 , with Oliver Messel as the interior designer . During the Bath Blitz of 25 / 26 April 1942 , one of the retaliatory raids on England by the Baedeker Blitz following the RAF 's raid on Lübeck , the Assembly Rooms were bombed and burnt out inside . After the cessation of hostilities in Europe , they were restored by Sir Albert Richardson , with work being completed in 1963 . The ballroom ceiling had to be repaired after it collapsed in 1989 . 
 In the 20th century several changes took place , with the Ballroom becoming a cinema , until the Society for the Protection of Ancient Buildings became the owners in 1931 . The building was restored by A Mowbray Green in 1938 , with Oliver Messel as the interior designer . During the Bath Blitz of 25 / 26 April 1942 , one of the retaliatory raids on England by the Baedeker Blitz following the RAF <a href='null_genetive' title='1'><mark>'s</mark></a>raid on Lübeck , the Assembly Rooms <a href='uninflect' title='2'><mark>were</mark></a> bombed and burnt out inside . After the cessation of hostilities in Europe , they <a href='uninflect' title='3'><mark>were</mark></a> restored by Sir Albert Richardson , with work being completed in 1963 . The ballroom ceiling had to be repaired after it collapsed in 1989 . 
In da 20th century several changes took place , with the Ballroom becoming a cinema , until the Society for the Protection of Ancient Buildings became the owners in 1931 . Tdabuilding was restored by A Mowbray Green in 1938 , with Oliver Messel as the interior designer . During thdaath Blitz of 25 / 26 April 1942 , one of the retaliatory raids on England by thedaedeker Blitz following the RAF  raid on Lübeck , the daembly Rooms was bombed and burnt out inside . After the cdaation of hostilities in Europe , they was restored by Sir Albert Richardson , with work being completed in 1963 . The ballroom ceiling had to b repaired after it collapsed in 1989 .