This paper presents a methodology for evaluating the photometric and colorimetric characteristics of internal building materials, for daylight evaluation. The assessment of these characteristics is crucial both for modelling materials accurately in daylight simulation tools and for building correct daylight mock-ups. The essential photometric and colorimetric parameters that influence the reflection of light from and its transmission through building materials are identified and described. Several methods for evaluating these parameters qualitatively and quantitatively are then proposed and discussed. Our new methodology was fused to create a database of materials in a freely accessible web tool which compares full-size materials to scale-model materials in order to help architects and lighting designers choose materials for building daylight scale models.