hi there,
as people have said this type of work is done early hours or overnight, also using sometimes quite large bits of kit, towers, cherrypickers etc, depending on the job required.
you will also find that shop frontage and fascias, usually fall into the window cleaners domain.
office frontage, is a service that is performed once every few years, and can be very costly to the client. we are involved in a contract at the moment where we are only cleaing a 10th of the building, 100ft up, will take a month to complete, and requires some heavy kit. and the invoice is obviously reflecting that.
that is why you dont see frontage cleaning be done all the time.
regards
martin