I live in a terraced house, next to the passage and my neighbour has access to her property by passing through my property, next to the kitchen. Like Hamster says, this is common practice. I have had no problem whatsoever with the arrangement. The only restriction I have is that i could not extend or put on the conservatory onto my kitchen.
When i first moved in, i was concerned too, but a marriage breakup etc meant that it was all I could afford. It was the best move ever. All 4 houses in our small block of terraces have no gates, we speak openly, bring each other's washing in if it rains, accept parcels for each other, lend out/borrow gardening tools etc. I have never lived in such a friendly neighbourhood.
compmare this to where I lived previously - detached houses, middle class neigbourhood, everything squared and clear cut and the only dialogue with neighbours was complaints about trees overhanging, visitors parking etc. i would not want to move back there.