Maintaining constant thermal conditions in building interiors requires substantial energy. Using phase-change materials (PCMs) with construction materials can improve thermal performance without increasing energy expenditure. Herein, shape-stabilized PCMs (SSPCMs) were used. We measured the thermal performance of a PCM sheet and established the melting- and solidification-temperature ranges at 19-26 degrees C. Three identical huts were examined using varying PCM levels under natural and heating conditions. In Hut A, no SSPCM sheets were applied; in Hut B, four layers of SSPCM sheets were applied to the floor; in Hut C, one layer of SSPCM was applied to the floor, walls, and ceilings. The results demonstrated that the application of SSPCM sheets improves thermal performance. For an equal number of SSPCM sheet layers applied on each side, the floor directly exposed to solar radiation showed the highest indoor temperature stabilization effect, followed by the walls and ceilings. Compared with Hut A, which served as the reference, the total power consumption using a heater decreased by 9.2% and 18.4% in Huts B and C, respectively. The effect of reducing heating power doubled when the applied area was expanded from the floor to the entire surface. Hence, effective PCM usage can entail large-scale application of SSPCM sheets to building surfaces. (C) 2017 Elsevier B.V. All rights reserved.