If you work in a high-rise building, how often do you see people outside cleaning the windows? If you’re not sure, it’s around once or twice a year, but it can sometimes be more – depending on the building. When you notice the hard-working abseilers outside cleaning away, it usually sparks up some conversation in the office, seeing these brave people dangling off the side of a building, literally hanging on by a rope. But outside that, it’s not something you usually might pay attention to On the other hand, knowing how often to clean high-rise building windows is important