We used one of
these (but got it from Toolstation as I was going there almost daily and it was a bit cheaper
) when we were renovating the new house so all the trades could get in without being around. It worked OK, you can change the combination whenever you need to. However, if someone rips it off the wall then they have a key for the house - but if they're going to do that then they probably wouldn't give too hoots about breaking in without a key.