In the iron and steel making process, hot rolling only accounts for approximately 10% of the energy consumption. Yet 1.5 to 2 GJ/t steel are consumed for hot rolling, and 80% of this energy is utilised for reheating of the slab. The rolling itself requires only 0.3 to 0.4 GJ/t1. Increasing energy costs and targets for the reduction of CO2 emissions provide a constant challenge for all high temperature process users to optimise their processes. In addition to raw material and labour costs, the costs for energy and environmental requirements play an increasingly important role. New technical solutions are required to improve the energy efficiency and reduce the energy consumption and CO2 emissions. The target of ArcelorMittal Bremen GmbH, Germany, and FBB Engineering GmbH is to optimise the hot rolling process from an energy point of view, reduce CO2 emissions, and reduce the operational cost of the reheating furnaces. Another important aspect is the increase in productivity by reducing the shutdown time of the furnace. This paper discusses how energy consumption and energy loss can be reduced in reheating furnaces of hot rolling mills by new lightweight refractory materials and a new lining concept for the skid pipe insulation.