My sister has one too and she babysat all of her grandchildren when they were babies. As soon as they could crawl up she started teaching them how to turn around and crawl backwards down the stairs.A friend of mine has one of those split level houses with 3 levels. The bottom has tile floors and the rest is wood. So she told me they worked on the stair skills early. They taught them how to go down safely because they just couldn’t realistically block everything off all the time. I would have been so nervous! Someone bought padding for my grandparents house because of all the little kids going up and down their split level too.