Literature shows that over the years numerous techniques for estimating development effort have been suggested, derived from late project measures. However, to the successful management of software projects, estimates are necessary throughout the whole development life cycle. The objective of this paper is twofold. First, we describe the application of case-based reasoning (CBR) for estimating Web hypermedia development effort using measures collected at different stages in the development cycle. Second, we compare the prediction accuracy of those measures, obtained using different CBR configurations. Contrary to the expected, late measures did not show statistically significant better predictions than early measures.