Generation III+ designs were meant to drive the ‘Nuclear Renaissance’ that was forecast by the nuclear industry from the late 1990s onwards. The central claim for the new technologies was that they would build on existing technology but the design, especially the safety systems, would be rationalized. This would mean that the plants would be safer than their predecessors, but simpler, therefore cheaper and less prone to construction delays. There would be a reliance on ‘passive’ safety, fabrication of large parts of the plant in factory-made modules and standardisation of designs. This report examines experience of constructing Generation III+ identifying the major problems met and thereby testing the claim that Generation III+ designs would be more buildable. We do not examine the claim of greater safety here, although we do note the differing approaches to improving safety. While the primary objective of this report will be to examine these claims of ease of construction, the analysis also brings evidence on three other important areas: standardization; generic design reviews and; future of light water reactor technology.