This paper considers the model of voluntary, consensus based standardization as developed through the British Standards Institution (BSI) and its contribution to learning and productivity growth. It discusses the significant role played by professional engineers in the model's introduction, its extension at home, and imitation overseas. It is argued that by 1931 the BSI catalogue of standards represented a considerable stock of codified knowledge whose growth reflected underlying aggregate technological opportunities, assisting in their transformation into technological advance. To help validate this claim we incorporate a measure of the size of the BSI catalogue of standards into an econometric model of aggregate productivity growth in Britain. We find that the growth of the standards catalogue is associated with a substantial proportion of labour productivity growth over the period . Estimates relating to the short-run dynamics involved are consistent with the idea that there are causal linkages running from standards to growth. When interpreting our findings, it is argued that the overall weight of historical evidence points to standardizationcoordinated through the BSI -as providing an important path of learning for the British economy over the period considered.