Houses often have a stop tap inside the house - sometimes under the kitchen sink - and another stop tap owned by the water company set into the ground just outside the boundary of the house. A little metal or plastic hinged door about 5 inches square can be lifted up to get access to it. Sometimes the tap handle is a couple of feet down and you need to lie flat to reach it unless you have one of these...
http://www.toolstation.com/images/library/stock/webbig/62757.jpg
Good luck...
Peccavi
June 2009