With the development of a knowledge economy, it is reasonable to assume that the level of innovation should be particularly high and that it should have a major effect on investment and productivity across all sectors, including the construction industry. For a valid assessment of the economic performance of the construction sector in terms of its productivity, it is important that the economic benefits for the sector from technological change are properly recognized but the impact of such benefits may be 'hidden' due to measurement issues, as innovative activity and investment in intangible assets have both gone unrecognized in official statistics. Much of the innovation in the construction sector is hidden from conventional measures and, for the UK economy, there is evidence that investment in intangibles may be even greater than tangible investment, if a definition of intangible assets incorporating spending on a broad range of knowledge-based assets including organizational capital, human capital, etc. is taken. While accurate data are difficult to determine, an appraisal of the potential for utilizing existing data sources and for improved measurement is presented.