I don't often agree with Norman but, this time, I agree with him twice over ;-)
Firstly, routine parking matters are now dealt with, within most large towns, by the local council. (In rural areas, traffic wardens may still do the job). So, it could be worth having a word with the relevant department. (As Ethel states, it's an offence to park a vehicle with its wheels on the kerb, except where there are signs specifically permitting this).
More importantly, it would seem that this guy is using his house for commercial purposes (i.e. the storage of trade goods or materials). I would doubt that he's got planning permission to do so. I suggest having a word with the planning department, to see if they're prepared to take any action (My feeling is that you're more likely to get a long-term solution to your problem from the planning department, than from the parking control department).
Chris