According to the forestry division, hardwood (Quercus semicarpifolia), preferred for its high caloric value, in the Thimphu region was exhausted way back in 1991 when still many household used firewood for cooking. An area of 180 hectares of hardwood in Chamgang,Helela and Gidakom marked out to last 30 years was wiped out in five years. That is about 36 hectares or 90 acres of wood in a year as fuelwood alone.