The airborne sound insulation of building structures is a subject of permanent interest of designing engineers and architects. Although the weighted apparent sound reduction index is in the final phase verified by measurements in already established buildings, semi-empirical methods have a potential of non-negligible financial savings in the building design phase. The paper presents a set of equations convenient for the calculation of the airborne sound insulation of single and double building structures which extends the Sharp’s method. The equations are derived by mathematical procedures but the purpose of this paper is to supply the reader with a prepared computational tool and that’s why the derivation is listed in different publications. The set of equations is compared with laboratory measurements and other methods both for single (EN 12354-1, Davy’s and Watters’ method) and double structures (Davy’s and Watters’ method).



















