Visual comfort study of a retrofitted building

Thermal renovation of buildings has other consequences than energy savings. In this project, a light framed renovation façade with a low U-value was added on existing heavy building envelop, for enhance its energy performance. Beyond energy saving questions we were interested by the impact of this retrofit solution on entering daylight quantity.  The problem was approached experimentally and numerically. The experimental study was conducted in a “PASSYS” test cell; a real sized experimental device with 5 adiabatic façades and one “removable test” wall that was used to represent an opening without shading device. The numerical part was done using Google SketchUp Pro v7 to input the 3D geometry model, and simulations were done using EneryPlus, DAYSIM/Radiance and a free, but commercial code.  The paper presents the confrontation of experimental and numerical data, issue of the cited three codes. A summary of inequalities and discrepancies close this paper.