This paper introduces a framework of decision support system on energy retrofit for existing buildings. To
rapidly and accurately measure the 3D geometry with thermal data of a building envelope, a hybrid 3D LIDAR
scanner was developed. An IR camera was integrated into the 3D LIDAR system to measure the temperature of the
building surface. Multiple degrees of freedom (DOF) kinematics were solved to integrate the two units to obtain xy-z coordinates and corresponding temperature data for each point. A GUI was developed to control the hardware
units (LIDAR, stepper motor, and IR camera) for data collection and to edit and visualize 3D thermal point clouds.
As-is BIM can be automatically created through recognizing all the components of the building envelope. After
converting file format into gbXML, the as-is BIM can be imported into energy analysis software to conduct building
performance analysis