Typical for single layer membrane structures is the less isolation against temperature and sound. A de monstration building is de veloped to dem onstrate the possibilities of membrane structures being more environmental and sustain able for conditioned indoor use. The solar and therm al principles of the basis of the skin of the ice bear are converted in the technical solution of a m embrane structure. A m embrane structure is developed based on a translucent multi layer, double cu rved and preten sioned system with high therm al isolation properties. The de monstration building shows different solutions of m embranes with im - proved isolating properties. The structural task is the development of a m ulti layer, double curved membrane with layers of different stiffness, load carrying and enviro nmental properties. The different solutions of coupled layers are designed and an alyzed. This includes the desi gn of the m embrane in relation to the different mechanical and thermal properties of the single layers as well as the mechanical connection of the layers. The main aspects are the position of the load carrying layer and the load carrying connection between the layers and the influence of the different tem - peratures of the single layers to the load carrying behaviour of the total system. Furthermore it needed to b e examined the influence of enclos ed air if one solution has an inner and outer load carrying layer similar to an inflated structure. The design steps towards a dem onstration building are presente d which are divided into the examination of the membrane materials available on the market for the functional layers, analysing of different layouts of the functional membranes, design proposals for the demonstration building and detailing of the multi laye r system including the the rmal active membrane and thermal isolation. Advantages and disadvant ages of the different solutions are discussed considering air flow, load carry ing behaviour, detailing, long term behaviour and m ounting on site.