A proof of concept of a monolithic concrete SPAR platform for FOWT was developed in the framework of the AFOSP KIC-InnoEnergy project (Alternative Floating Platform Designs for Offshore Wind Towers using Low Cost Materials). The AFOSP project consisted in a series of experimental and numerical studies aimed at proving the feasibility of the concept and demonstrated promising CAPEX and OPEX reductions. The members of the AFOSP consortium are: GNF, University of Stuttgart and UPC. The experiments comprised a set of hydrodynamic tests performed in the CIEM wave flume facility at the UPC, with a 1:100 scale model assuming Froude similitude. The complete experimental campaign included free decay tests, a set of 22 regular wave trains of different periods to determine the RAO’s and another set of 21 regular and irregular wave trains in conjunction with a mechanical wind device, simulating the mean thrust force exerted by the wind turbine. Numerical studies were intended to verify that the design is stable when subjected to design load case (DLC) according to the IEC. These studies consisted in coupled dynamic simulations including the mooring system, the controller and the structural dimensions for a particular location, using the certified coupled aero-servo-hydro-elastic code FAST. IEC load situations include different environmental conditions and technical conditions of the floating system including failure cases.