Phase Change Materials (PCM) can be incorporated into various building components to increase their thermal mass to reduce energy consumption and to perform peak load shifting. This work shows the benefits of PCM when incorporated in walls, ceiling, and in combination with PCM underfloor heating system using two different types of PCMs. The use of higher melting point PCM with the underfloor heating system allowed significant peak load shifting, while using lower melting point PCM in the walls and ceiling provided the comfort needed in the building. Two identical huts built at Tamaki Campus of University of Auckland (New Zealand) are modelled using the software EnergyPlus. The simulations results are validated against experimental data obtained from two office size constructions. Ten days period is analysed, showing for the first time successful morning and evening peak load shifting with energy and cost saving of 32% and 42%, respectively. (C) 2017 Elsevier Ltd. All rights reserved.