Historical
BS EN 771-3:2003
Specification for masonry units. Aggregate concrete masonry units (dense and light-weight aggregates) (British Standard)
This EN specifies the characteristics and performance requirements for the physical and mechanical properties of aggregate concrete masonry units made from dense aggregate, lightweight aggregate or a combination of both. Units conforming to this Part of this EN are used exposed or non-exposed in common or facing masonry in building or civil engineering works.
British Standards Institution [bsi]