In order to refurbish the glass roof of an atrium in an administration building, industrial climbers from the Membranteam installed a work platform net as a temporary assembly level. As it was only possible to access the building through doors sized 2,20 m by 1,40 m, we worked with the very slender special machine, "Spider", which is able to pass through any standard doorway. In order to install the working platform nets, a very innovative assembly concept was needed, as there were none of the “usual” anchor opportunities.