Cellars, Supply Pipes and Old Stopcocks
In plenty of older Brighouse houses the mains supply enters at cellar level and the stopcock is down there with it. That is the first place we look when the meter keeps turning: the incoming pipe, the stopcock itself and the first few joints after it.
Old stopcocks deserve a mention of their own. They are often seized from years of being left alone, and one that will not turn makes any leak harder to manage. If yours is stiff, leave it rather than forcing it; freeing or replacing it is part of the job.