Complex sentence: Until 1995 the area consisted of 5 21-floored post-World War Two flats-between 1995 and 2004 they were redevloped which involved knocking down the 5 towers and building 90 year housings, developed by HAT housing.
Split into simpler sentences: Until 1995 the area consisted of 5 21-floored post-World War Two flats. However, between 1995 and 2004 they were redevloped which involved knocking down the 5 towers and building 90 year housings, developed by HAT housing.