Planning documents say the move would create 40 more full-time jobs at the plant at Alexandra Dock.
A multi-purpose manufacturing building is proposed along with a small staff welfare building.
Hull City Council will decide whether to grant permission for the development.
With the expected 40 new employees, the Siemens site would employ 1,624 people in total, according to the planning application.
A documents says "the main building is intended to extend the production and repair capabilities of the site”.
Air source heat pumps will be used instead of gas fired boilers, according to the Local Democracy Reporting Service.
The application says the expanded facilities for Siemens “would be of significant economic, social and environmental benefit” to Hull.
Workers at the plant build 108m (354ft) long wind turbine blades by hand.
In July, about 300 workers at the factory were balloted for strike action in a row over pay.
Last week, the union Unite said the dispute had been called off after it had secured a deal worth 8.4%.
