We began the destruction of the balcony immediately after moving in..
And then thought, after we read the blocks rules, we should let them know that we are going to make a lot of noise redoing the balcony. Better to inform them than risk making enemies of the neighbours. So we filled out a form and gave it to the office of the directors, who asked for details of everything. So we drew a little picture and told them exactly where we were going to drill holes etc. And then we waited. And waited.. for 2 weeks. Whereupon we were told that we could go ahead, as long as it wasn't going to change the appearance of the flat from the outside. Well being as we are 9 floors up there are few people who can look in the windows. Besides we aren't changing it massively. So this is what we lived with while we waited for the permission.
So best to read rules before considering any work in the building, and much as we enjoy living in a building site, sometimes its better to ask about building permissions before you take things apart... just in case.