It depends on which part of the house. From outside the house use a power washer to blast away the mold and stains. Apply a mixture of 1 part household bleach to 4 parts water to kill any residue of mold left. Inside the house, your only option is to apply the same mixture of household bleach to the mold surface for 15 minutes before cleaning off with a rug. Bleach can be very damaging if not used properly or even unsafe when mixed with ammonia. Indoors, use bleach in a well ventilated room and with care.
