This European Standard deals with the requirements and the basic performance criteria for blocks made in expanded polystyrene (EPS), used in conjunction with precast concrete beams in compliance with EN 15037-1, with or without cast-in-situ concrete for the construction of beam-and-block floor systems. EPS block may be totally made in EPS or combined with different materials such as plaster or wood wool. If EPS is combined with other materials, these materials should not contribute to more than 50 % of the mechanical resistance of the block. If not, the block is covered by EN 15037-5, Precast concrete products - Beam-and-block floor systems - Part 5: Lightweight blocks for simple formwork. Examples of typology of floor systems are given in Annex B of EN 15037-1:2008.