Wind industry is developing fast, moving from onshore to offshore and from shallow water to greater depths. At the same time, it is facing significant cost challenges. There are certain advantages to placing wind turbines offshore: better wind resources, economies of scale and increased public acceptance. The cost of traditional substructure solutions for shallow waters, such as monopiles, is greatly increasing with the depth. At the same time, reports show that considerable wind resources could be accessed in deep water, if alternatives to bottom fixed substructures are developed, such as floating wind turbines. Traditionally, their support hulls are manufactured of welded steel plates and represent a major contributor to the final cost of energy. Meanwhile, reinforced concrete is the most utilized material on our planet, in multiple industries, especially in large scale applications. However, the idea of possible cost reductions boosted by the use of alternative construction materials, has received very little attention in the offshore wind industry, with no full scale attempt and only one prototype, to the present date. Two reinforced concrete floaters have ever been built in the offshore oil and gas. Another option for reducing the total cost of floating wind energy could be utilizing large scale turbines which harness more wind. Furthermore, these suggested cost cut alternatives could be coupled into a large scale reinforced concrete floating wind turbine. The present work considers the design and analysis towards an optimizable baseline, of a braceless reinforced concrete semi-submersible supporting a DTU 10MW reference wind turbine. Initially, an extensive literature review is conducted and a design basis is established, given limited previous experience exists. Following, simple analytic formulas are applied to determine the main characteristics of the floater, in terms of its stability and motions, relevant for ensuring an adequate operation. Next, numerical analysis tools are used to confirm these findings. With the determined hydrodynamic and static loads, a quasi-static linear structural analysis with constant material properties is conducted. The floater is modeled as shell elements. The resulting stresses are post-processed based on the actual non-linear material behavior, for the ULS. A corresponding bill of quantities and materials cost estimate are developed, together with an assessment of the CO_2 impact. Consequently, the main conclusions and advice for suitable future research are formulated.