The global infrastructure expansion is propelling the construction sector towards increased cement usage. However, cement production reduces natural resources and affects the living environment by emitting significant greenhouse gases. Reusing industrial waste in construction materials should be considered to promote sustainable construction practices. This study evaluated the possibility of replacing cement with fly ash in civil concrete to increase the efficient use of natural resources and minimise environmental impact. The study proposes varying the proportion of fly ash in the concrete mix (ranging from 0% to 40%) and examining its effect on the final compressive strength of low-calcium fly ash concrete (FAC) under high-temperature curing conditions. Evaluation parameters include mass loss under dry conditions, wet and dry densities, and the maximum compressive strength attained to assess the durability of FAC. Preliminary results indicate that curing FAC specimens at 70°C enhances compressive strength. Furthermore, FAC demonstrates marginally higher wet density than traditional concrete, highlighting its versatility as a construction material. The study recommends prioritising FAC usage in projects exposed to sunlight, considering its cost-effectiveness and environmental advantages. These initial insights provide valuable experimental data for advancing FAC utilisation in residential construction.