A web tool for the choice of daylight scale model materials

This paper presents a web tool that has been developed in order to help architects or lighting designers to choose materials for the building of daylight scale models. Those scale models are built in order to qualify or quantify, under real or artificial skies, the daylight penetration and distribution in buildings. The essential photometric and colorimetric parameters that influence the light reflection and transmission of building materials were identified and several methods, for the qualitative and the quantitative evaluation of these parameters were studied. As a result of this study, the web tool proposes two input possibilities. The first one is the simplest: the user chooses the full size material in a database and the web tool immediately proposes a list of scale model materials. The second one is based on a complete input of the full size material characteristics: its colour that can be measured or identified by a colour code (RAL, NCS, ⋯) and its reflexion mode and its homogeneity that are then qualitatively described. In this second case, again, the tool proposes a list of selected scale model materials and the user can then choose a material in that list in accordance with the main objectives of his daylight study. In addition, the web tool proposes, as illustration, RADIANCE simulation results like illuminance values, in a reference office room with walls made of the full size material, and animations showing the importance of wall lightness on inside daylight distribution.