The main advantages of floating greenhouses compared to greenhouses on solid ground are the possibilities for multiple use of space and for energy saving. As in the coming years large area¿s in the Netherlands will be necessary to create water storage, the capability to give these areas an additional function by facilitating crop production on the water will prove valuable. By using the capacity of the water under the floatation system for heat storage in addition to an aquifer, a cost effective way to save energy can be provided. For the integral design of floating greenhouses, several key questions have to be answered. An expert system has been set up to support the design engineers with dedicated guidelines for the integral design of floating greenhouses. The system is a software tool that contains relevant information on greenhouse construction, energy systems, material properties, floating elements etc. and guides the engineer by a set of relevant questions in a structured way.