I wouldn't recommend it.
Not only is there a decent chance of survival with significant damage, mutilation, paralysis, etc. even for a pretty tall building, but the people who've survived that I've read up about have all described that the moment they were falling was absolutely terrible and they regretted it a lot in that moment. Even people who really wanted to end things. You don't want your last moment to be regret and utter and complete fear.
I'd also say, don't do it on impulse. If you're going to CTB you should think about it carefully. Weigh it carefully. It's an important decision. I am fully supportive of people who've reasonably decided that they're going to end it after long and careful consideration. But I think it's important to give it the proper time and consideration and never do it just on impulse. And I speak as someone who has had the same overwhelming urge to do it at times.