No apartment owner shall do any work which would be prejudicial to the soundness or safety of the property or reduce the value thereof or impair any easement or hereditament or shall add any material structure or excavate any additional basement or cellar without first obtaining the consent of all the other apartment owners. Explanation.—In this section, reference to apartment owners shall be construed, in relation to a multi-storeyed building in any block, pocket or other designated area, the apartment owners of the concerned multi-storeyed building in such block, pocket or other designated area.