This dataset represents the foundation construction and equipment installation for a single offshore wind turbine unit with a rated power of <3 MW. During the construction and installation stage, the main material inputs include concrete, reinforcing steel, structural steel, sacrificial aluminum alloy anodes, rubber fenders, and sandbags, while energy inputs mainly consist of diesel fuel and water used for construction and installation activities. In the decommissioning and end-of-life treatment stage, it is assumed that metallic materials, including reinforcing steel, steel, iron, aluminum, and copper, are recovered at a rate of 90%. Materials such as resin and rubber are treated by incineration, while other materials are disposed of via landfilling. The data are primarily derived from publicly available literature and empirical experience.