Nano-enhanced phase change materials (PCMs) have attracted increasing attention to address one of the key barriers (i.e. low thermal conductivity) to the wide adoption of PCMs in many industrial applications. This paper discusses the generic problem and key issues associated with appropriately using this new class of materials in buildings for effective thermal management and improved energy performance. An overview on major recent development and application of nano-enhanced PCMs as thermal energy storage media is provided. A case study based on a PCM ceiling ventilation system integrated with solar photovoltaic thermal (PVT) collectors is then performed to evaluate the potential benefits due to the dispersion of copper nanoparticles into the PCM base fluid of RT24. The results showed that this nano-enhanced PCM has higher melting and solidification rates than that of the pure PCM. Compared to the use of the pure PCM, 8.3% more heat was charged in and 25.1% more heat was discharged from the nano-enhanced PCM under the three winter test days. More research is needed to understand the fundamental mechanisms behind the PCM thermal conductivity enhancement through the dispersion of nanometer-sized materials and to investigate how these mechanisms drive building performance enhancement.