Glass (Flat Glass)

Glass is widely used in construction due to its translucency and ability to be molded in any shape. Flat glass (soda lime silicate glass) is the most widely used glass type, but glass fibre also find application in construction as reinforcement and glass wool insulation. Flat glass is widely used in windows and facades, but its recycling potential is underutilized. In manufacturing, reduction of energy use is achieved by adding cullet (recycled glass) to the raw mix, which lowers the melting temperature. Remanufacturing is common, with up to 26% of raw materials in the EU coming from cullet, mostly from internal waste. Recycling of pre-consumer cullet into other products like glass wool is also practiced.

At the end of life, reuse of flat glass is rare due to quality assurance concerns, although it is technically feasible. Repurposing is more common, with cullet used in concrete, ceramics, and asphalt. Recycling in a closed loop is limited (0–5%) due to contamination and challenges with separating the glass from other construction and demolition waste. Improving separation technologies could significantly enhance recycling rates.