Thermochromic and retro-reflective materials

Several innovative coatings for buildings have been developed over the past decade for increasing energy savings and mitigating Urban Heat Island effect. Among such solutions, retro-reflective (RR) materials were proposed for reducing cooling energy demand especially on Cooling Dominant Zones: they reflect the incident radiation towards the incoming direction, damping down inter-building effect. In addition, thermochromic coatings (TC), which modify their colour and reflectivity by temperature, are proposed also on Heating Dominant Zones, improving efficiency of buildings throughout the year. This chapter gives a comprehensive review of the recent developments on TC and RR including applications, future developments and limits.