NZS 3101:2006 Concrete Structures Standard - Part 1: The Design of Concrete Structures sets out minimum requirements for the design of reinforced and pre-stressed concrete structures. Part Two, Commentary on The Design of Concrete Structures, explains the provisions of Part One, summarises technical background and suggests approaches which satisfy the intent of the Standard. Amendment 3 to NZS 3101.1&2:2006 involves significant revision and the introduction of new material. It has been primarily developed to address recommendations from the Canterbury Earthquakes Royal Commission. In addition, errors in the original published standard and commentary have been corrected and included in this amendment.