This standard determines the subdivision into construction elements for the systematisation, classification, coding etc. of information that covers the physical elements of the building and associated outdoor constructions. The subdivision can be used for building specifications, statistics and transfer of knowledge relating to costs, useful properties, duration etc. The subdivision can also be used in connection with reference systems for marking building elements on drawings, charts etc. and in the completed building. Digits 0, 1, 8 and 9 are not used for building elements at one-digit level in the standard. These digits are used for other purposes as stated in NS 3453.