LEED is a point-based rating system; points are earned for building attributes considered environmentally beneficial. LEED differs from other rating systems in that it has quantified most of the "green credits." For example, 5% of the building materials must be from salvaged materials to earn a point for the salvaged materials credit.
LEED 69 points (70 for LEED Canada) covering six topic areas. Each topic area has a statement of associated goals.
Site Development: minimize storm water run-off, encourage car pooling and bicycling, increase urban density and green space
Water Efficiency: eliminate site irrigation, reduce water consumption, minimize or treat wastewater
Energy Efficiency: reduce building energy consumption, use renewable energy, eliminate ozone-depleting chemicals, commission building systems
Material Selection: minimize construction waste, re-use existing building façade, use recycled and salvaged materials, use renewable construction materials and design and build more durable buildings
Indoor Environmental Quality: incorporate daylighting, use low off-emitting materials, provide operable windows and occupant control of work space, improve delivery of ventilation air
Innovation in Design: use a LEED Accredited Professional, greatly exceed the requirements of a credit, incorporate innovative environmental features not covered in other areas, develop a green education plan