Green building, also known as sustainable building, is an approach to designing, constructing, and operating buildings that are environmentally responsible and resource-efficient. The concept of green building takes into consideration the entire life cycle of the building, from design and construction to operation and maintenance, with a focus on reducing the environmental impact of the building.

The goal of green building is to create buildings that are energy-efficient, resource-efficient, and environmentally responsible, while also providing a healthy and comfortable living and working environment for the occupants. Here are some of the key features of green building:

1. Energy Efficiency: Green buildings are designed to be energy-efficient, using renewable energy sources such as solar power and wind power, and utilizing technologies such as energy-efficient lighting, heating and cooling systems, and insulation.

2. Water Efficiency: Green buildings are designed to be water-efficient, using technologies such as low-flow toilets and faucets, and utilizing rainwater harvesting and other techniques to conserve water.

3. Sustainable Materials: Green buildings use sustainable materials, such as recycled and renewable materials, to reduce the environmental impact of the building.

4. Indoor Air Quality: Green buildings are designed to provide a healthy and comfortable indoor environment for the occupants, with features such as improved ventilation and air filtration systems.

5. Waste Reduction: Green buildings incorporate waste reduction techniques, such as recycling and composting, to reduce the amount of waste produced by the building.

6. Site and Location: Green buildings are designed to minimize their impact on the surrounding environment, with features such as green roofs and landscaping, and by locating the building in a way that reduces the need for transportation.

In summary, the concept of green building involves designing and constructing buildings in a way that is environmentally responsible, resource-efficient, and sustainable. Green building practices help to reduce the environmental impact of buildings, while also providing a healthy and comfortable living and working environment for the occupants.