CPV code 45222200 designates Engineering work for military installations in the Common Procurement Vocabulary (CPV 2008), the EU classification used to describe the subject of public contracts.
45222200 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 45222000 (Construction work for engineering works except bridges, tunnels, shafts and subways).