Height is critical when choosing a telescoping ladder, or any ladder, for that matter. Buy one that is much taller than you need, and it might not fit well in the area where you will be working. On the other hand, get a ladder that’s too short and you still won’t be able to reach what you need to reach—or things will become dangerous when you try to extend your reach in an unsafe manner. The average height for telescoping ladders is about 12 to 12½ feet, but you can find some that are much shorter and also a lot longer. A good 12½ foot telescoping ladder will work perfectly for most home improvement projects. In the end, too long is better than too short, since having a ladder that is too long is inconvenient, but you can usually still get the job done.