Why is the bailiff sitting outside the house in his van for hours at a time?

The bailiff has no work.

Similar to a minicab driver, he is waiting for his next job to show on his device.

There is little point burning fuel driving nowhere, when the debtor might return home.

If a bailiff is loitering near your home, menacing, harassing you or acting suspiciously in the neighbourhood, then call police reporting a harassment in progress with a suspect on the scene.^[1]

Make a video, or take photographs of the bailiff and his vehicle in evidence.

^{[1] Section 2A of the Protection from Harassment Act 1997}