The crew was taking part in a competition which involved manoeuvring close to a cherry picker device. The flight path to the target required a quick descent to stay on course for the cherry-picker which was extended to 70 feet above ground level. The pilot made an approach to the target from 400 feet above ground level to about 100 feet but was unable to track to the target. The pilot activated the burners for his recovery from the descent as he passed the cherry picker, but the balloon descended to a lower height than anticipated and struck the roof of a house. When the basket was retarded by the roof, the envelope lay over downwind. The burners were still operating and burned a large hole in the envelope mouth. The balloon remained under control and landed in the next suitable paddock.