Alright, I remember being able to do this before in Sims 4, but for some reason, it isn't working now. Consider the following... This is the third floor in a three-floor sample building. The balcon...
They go up and down, no problems... I did not 'remove' the fence using b+ctrl though, I right clicked it, removed the entire side wall (hence, keeping the 'room') and then afterwards replaced the one missing piece of fence in the corner, maybe that helps?