An efficient thermo‐acoustic insulation material was developed for ceiling/roofing through tailoring of natural fiber (coir) and industrial solid waste (fly‐ash) by polymer matrix. In the conventional system, the insulating (ceiling) materials are placed below the shielding (roofing) component of the conference hall, theaters, and so on. The advancement of the present study is to integrate the shielding and insulation layers in a single entity by tailoring the waste materials. The composites were fabricated using coir fiber and fly‐ash, then they were tailored by varying the applied pressure (0–150 kg cm −2 ) and characterized the effect of sound absorption, transmission loss as well as the thermal conductance and thermal resistance. Meanwhile, the structural integrity and weathering properties of the composites were studied through physio‐mechanical, hardness, and UV–Vis characterization. The composite sample compressed at 50 kg cm −2 (CF‐50) shows the sound absorption coefficient ( α ) of 0.94 and transmission loss in the range of 10–12.5, which infers that the sample is categorized under class A ( α , 0.90–1.00). Besides, all the composites possess low thermal conductivity in the range of 0.05–0.09 Wm −1 k −1 and better thermal stability up to 300°C. The tailored composites using solid waste and natural fiber not only benefit the structure but also help in reduced environmental contamination, minimal cost, and promote the green building initiatives as well.