British Standards Document
BS EN 771-1
Specification for masonry units. Clay masonry units

https://doi.org/10.3403/30203891U

BS EN 771-1 is maintained by B/519/1. The current release of this standard is:

BS EN 771-1:2011+A1:2015 Specification for masonry units. Clay masonry units

https://doi.org/10.3403/30203891 (published 31/10/2011)

This standard is available from the following sources:

Other historical versions of this standard document also exist:

BS EN 771-1:2011 [current until 31/03/2016]
BS EN 771-1:2003 [current until 31/10/2011]