The reduction of energy consumption in building and construction materials has become an important issue, and many efforts are being carried out to increase energy efficiency. Over the past decade, various types of concrete materials, in particular, have been studied and modified to increase their energy efficiency. The main objective of this study is to develop eco-friendly insulating concrete using recycled aggregate and organic fibers. Different types of recycled aggregates obtained from waste concrete are utilized, and bio-based organic materials are also used as fiber for the concrete matrix. By examining the characteristics of recycled aggregates and concrete, a method will be developed for creating high-performance insulating materials that can reduce energy consumption and have a positive impact on environmental problems. Void distribution, computed tomography (CT) images, and probabilistic methods are used to undertake a detailed investigation of the characteristics of insulating concrete made with different aggregates. The material responses of insulating concrete with different components are complementarily evaluated using experiments and numerical simulation tools. Using these results, we identify the optimal void size, distribution, and shape in order to enhance the insulating and strength performance of the insulating concrete specimen. From the obtained results, the proposed multi-scale analysis and methodology for developing advanced insulating concrete is demonstrated.