Posted By Karen Wilson I know I have posted this request previously - but can anyone suggest a good fall arrest system, or controls for considering working at height, when installing sash windows from within a property? e.g. working on the fourth floor, remove old sash window (bringing it into property). Then you have a large open space into which you have to position first the frame, then the upper window and then the lower section of the window. What reasonable measures can be put into place to prevent the lads from falling through the open window??? Any help appreciated. Karen