I'm curious at what ages everyone felt confident in their kids' ability to navigate a set of stairs by themselves? DS is 3 and is physically able to go up and down by himself. And for small sets of stairs (like 3 steps off the deck or steps on play equipment) we let him go by himself. But I'm not sure when I can trust him in our house.

Our main set of stairs is a straight staircase with wood floors. DS can be accident prone and doesn't really pay attention to what he's doing sometimes. For example, he'll pay more attention to trying to grab the bannister before he can reach it, and practically falling off the first step.