Temporary lightweight buildings are widely used for post-earthquake resettlement, sporting and expos events due to their high flexibility, mobility, recyclability, rapid installation and disassembly, and low cost. However, their energy efficiency is compromised due to high susceptibility to environmental influences. This research addresses this challenge by integrating temperature adaptive radiative cooling (TARC) painting on the external walls of such structures. To evaluate the energy-saving effects of TARC, we conducted a numerical simulation on temporary buildings previously used in the Wenchuan earthquake-stricken area. Three scenarios were examined: 1) a building with commercial white (CW) painting as a reference, 2) a building with TARC paint applied on the roof and external walls, 3) a building with a mix of TARC-CW paintings optimised for maximum return on investment. The simulations compared the three scenarios across different seasons to evaluate their energy-saving potential and impact on indoor thermal comfort. The simulation results establish a feasibility analysis method for reducing the energy consumption in buildings with TARC paints. The outcome of this research also contributes to the design and experimental research of TARC paints in future.