Attempts to advance standards for measuring daylight in buildings beyond the daylight factor (DF) have, so far, met with limited success. One reason is that it often appears to be impossible to advance the DF methodology by incremental means. It is now widely acknowledged that climate-based daylighting modelling (CBDM) offers the means to make a major advancement in the evaluation of daylight in buildings. Whilst metrics founded on CBDM will almost certainly form the basis for daylight standards in the medium term, there is a pressing need to progress current practice in the short term. Here, the authors propose that a long-overlooked method linking the estimation of daylight provision to prevailing climate be used as the basis for guidelines and standards.