CPV code 45212225 designates Sports hall construction work in the Common Procurement Vocabulary (CPV 2008), the EU classification used to describe the subject of public contracts.
45212225 is a leaf code — the most specific level of its branch — so it can be used directly as the main CPV code of a contract notice. If it does not quite fit, check the neighbouring codes under 45212220 (Multi-purpose sports facilities construction work).