The aim of this article is to design, precisely and fully detailed, the Control Room of a Ballast Actuation System of a marine Tidal Energy Converter. The design would respond to the detail design stage of any shipyard for its subsequent manufacture. During the following lines, the authors have analysed the Ballast Actuation System, not only from a conceptual way, but also from the detailed design point of view, so it has been considered necessary to complete it, with a study of a technological nature, in which industrial (reducing the cost and increasing reliability) solutions have been developed for measuring and driving systems. To elaborate the 3D detail design of the pump room, a topological design has been introduced for allowing a quicker evaluation of different design alternatives. All the machinery, piping, supports and auxiliary structures have been modelled in order to evaluate the quality of the conceptual and initial design. The primary structure, as well as the location of the equipment, have been carefully studied and analysed. The P&ID (Piping and Instrumentation Diagrams) and access drawings have been followed in order to model the 3D pipe routing, supports and auxiliary structure. The 3D components have been defined from its main features (element ID, supplier, description, weight and centre of gravity) and its geometry (library or geometric macro model), provided by the supplier. All this work has been carried out with the intention of not only assess different alternatives, but also to generate at any time the information for manufacturing and mounting.