So, LEED is a grid that helps us obtain a maximum gain of money, health conditions and restrictions on earth pollution. If there is a house to build in Canada, we must do the excavation and that earth is usually brought to a landfill. But, if you want to stay within LEED standards, that earth must be left on the site. Also, if you have to demolish a building, you must use and demonstrate that you recycled all materials in the construction. Also, that you used the maximum quantity of material possible from the old building to the one being built.