Within the FP7 project “3ENCULT – Efficient Energy for EU Cultural Heritage”, the school building “Höttinger Hauptschule” in Innsbruck (Austria) is one of the 8 case studies for demonstration and verification of energy efficient solutions. Besides the reduction of thermal losses, a special focus will be on the optimisation of daylighting and energy efficient artificial lighting with high priority of conservation-compatibility for all of the interventions. New software for visualization (VIVALDI by Zumtobel) is used. The principle behind it is to evaluate the luminance of interesting areas of calibrated HDR (High Dynamic Range Image) photos taken of rooms with prototypically installed systems. As the electric consumption of the artificial light is well known, the saving potentials of different lighting solutions can be evaluated.