Bob loves it outside and I swear given the choice he'd be an outside bun. Kizzy wanders out, checks to see if there is any chaos she can cause then wanders back. But Kizzy is definitely an indoor bun and where Kizzy goes Bob will always follow.
Strangely, Bob will race around the garden, into the dinning room around the living room back through the dinning room and back out into the garden at high speed, but he will not cross the threshold from the living room into the hall - ever - not even once in all the two and half years we've had him.
Kizzy will try and dodge around us to get into the hallway at every opportunity I think she finds it funny to watch the silly humans chase her upstairs. On the rare occasions she manages to get by us without us noticing she will sit at the top of the stairs and thump until one of us dutifully runs upstairs after her. We get in reach of the top step and she binkies away into the bedroom.
So neither bun is scared of the great outdoors but Bob is scared of the hallway