Large quantities of HBCD-containing Expanded Polystyrene (EPS) had been used in External Thermal Insulation Composite Systems (ETICS) from the 1970s until the flame retardant HBCD was banned in 2016 for being a persistent organic pollutant (POP). According to the Basel Convention, a solvent-based process is the best available technology for POP-containing waste. Such processes are subject to an impurity limit, thus requiring a pre-treatment of the input material. Therefore, a sequence of comminution and sorting technologies was designed and tested with real-life ETICS demolition waste. Three specimens were used as input material. Following an initial analysis, the demolition waste was comminuted, examined, and a sorting technology was selected. The resulting material fractions were weighted and analysed. The lightweight fraction (target: sole EPS) was additionally tested for its purity. The designed process achieved an efficient material disintegration and separation resulting in a purity of the lightweight fraction of up to 93 wt-%. This result represents a major step towards the circularity of EPS via solvent-based recycling.