•Microsilica increase mechanical properties without affect acoustic properties.•Higher microsilica percentage, impact in a porosity smaller.•With 5% of microsilica, better is the thermal conductivity.•It is possible to obtain a 87.85% of porosity with 0.20% of microsilica. Gypsum is an ancient material of great abundance that can be used as acoustic and thermal insulation protection in civil construction, especially when water-based foam is added to it, improving these properties. This research presents gypsum foam processing using a direct casting method with additives from natural sources, thus avoiding environment degradation. The results showed that gypsum foam has a potential for thermal and acoustic insulation and is more effective than other materials currently being used. Although, the material mechanical strength decreases when only water-based foam is added, further microsilica (MS) addition improved its mechanical strength without spalling its acoustic absorption and thermal conductivity.