Open Source Software for Daylighting Analysis of Architectural 3D Models

This paper examines the viability of using open source software for the architectural analysis of solar access and over shading of building projects. For this paper open source software also includes freely available closed source software. The Computer Aided Design software - Google SketchUp (Free) while not open source, is included as it is freely available, though with restricted import and export abilities. A range of software tools are used to provide an effective procedure to aid the Architect in understanding the scope of sun penetration and overshadowing on a site and within a project. The technique can be also used lighting analysis of both external (to the building) as well as for internal spaces. An architectural model built in SketchUp (free) CAD software is exported in two different forms for the Radiance Lighting Simulation Suite to provide the lighting analysis. The different exports formats allow the 3D CAD model to be accessed directly via Radiance for full lighting analysis or via the Blender Animation program for a graphical user interface limited option analysis. The Blender Modelling Environment for Architecture (BlendME) add-on exports the model and runs Radiance in the background.