The article presents the methodology of the representative elementary volume definition for 1 m long whole core segments. Scientific articles focused on factors controlling elastic properties are analysed. Terms of additivity and nonadditivity for physical properties of rocks are discussed. The algorithm of core sampling including drilling out of three perpendicular core samples for estimation of elastic anisotropy was used. Porosity values of 1 m long whole core fragment evaluated in two ways using original core samples in the first approach and core samples having volume 133 cm3 in the second way have been compared. Peculiarities of scale effect of porosity in core samples of limestones are analysed.