This study investigates the thermal and acoustic insulation properties of lightweight concrete modified with nanosilica and porcelanite aggregates. Eight lightweight concrete formulations with varying nanosilica content (0%, 1%, 1.5%, and 2%) and aggregate sizes (4 mm and 5 mm) were developed and tested. The results indicate that incorporating nanosilica significantly enhances both thermal conductivity and acoustic impedance. Concrete samples with 4 mm porcelanite and 1 % nanosilica achieved a thermal conductivity reduction of 24.85 %, while samples with 5 mm porcelanite and 2 % nanosilica demonstrated an 8.42 % increase in acoustic impedance. These findings underline the synergistic effects of nanosilica and aggregate size, providing insights for optimizing lightweight concrete performance in thermal and acoustic insulation applications.