The pilot had been conducting a series of joy flights, as part of a school fund raising program. Refuelling equipment was positioned some 100 metres from the passenger loading area. The pilot had offered to take two boys with him as he air-taxied the aircraft prior to refuelling. After take-off from the passenger area, the pilot decided to carry out a short local flight, but as he turned back towards the fuel dump, the engine lost power. The pilot was unable to reach a cleared area and attempted to land in a street. The helicopter collided with trees, then struck the roof of a house before coming to rest on its side in the driveway of the house. During joy flight operations, the pilot did not rely on the fuel gauge inside the aircraft. He briefed an assistant, who relayed information relating to the fuel remaining by reference to sight gauges on the fuel tanks. There had evidently been a communication breakdown between the assistant and the pilot as to the amount of fuel remaining prior to the last joyflight. The subject flight had been made on the spur of the moment, in order to give two handicapped children an opportunity to see their school from the air. The engine had failed from fuel exhaustion while the aircraft was over an area which was unsuitable for a forced landing.