A green building can also be referred to as a sustainable building.  Green buildings are structures designed, built, renovated, operated, or reused in an ecological and resource-efficient manner.  A Green or sustainable building is designed to meet certain objectives such as improving employee productivity; using energy, water, and other resources more efficiently; protecting the occupant's health; and / or reducing the overall impact to the environment.

Features that include Green building design are as follows:

• Site location: consider such things as walkability,  public transit, and native landscaping.
• Energy efficiency: Building orientation; passive energy use such as solar, wind, or geothermal; use of natural lighting; properly sized HVAC (heating, venilation, and air conditioning) system; high R values (insulation) in ceilings and walls, minimal glass installed on east and west building orientation
• Water efficiency: Dual plumbing design to use recycled water for toilet flushing; a greywater system that recovers rainwater for site irrigation; recirculating systems for centralized hot water; Point-of-use hot water system
• Material efficiency:  use of I-joists, SIPS (structural insulated panels), and cement (hardiplank) fiberboard; forest certified or sustainably harvested wood products; recycled or reused demolition or construction materials
• Occupant health safety: low or no VOC's (volatile organic compounds) and formaldehyde; high efficiency ventilation system; use of materials resistant to microbial growth; effective drainage from roof and surrounding landscaping; high quality ventilation in bathrooms; proper drainage of air-conditioning coils; design systems to control humidty levels.
• Operation and Maintainence: Built to certification standards.