A recycling method for gypsum waste from reconstruction and destruction works has to be developed to precipate contaminants. The resulting recycling gypsum should be used for the production of new plasterboards. By using secondary raw material the gypsum industry would reduce its dependence on natural resources, which are going to run short during following decades. Waste industry would profit by transforming waste, which usually gets landfilled, to a saleable good. Furthermore gypsum waste causes problems at landfills. It often leads to increased sulphate values, which exceed the mandatory limit values. By several practical tests a recycling process for producing material that conforms to the quality requirements of the gypsum industry was developed. Based on this recycling concept the cost-effectiveness was calculated to support the participating enterprises in deciding against or in favour of implementing the project.