A green building is designed to reduce its impact on the environment. That means using less energy, less water, and fewer resources. It also means creating healthier indoor spaces and considering the building's entire life cycle, from construction to demolition.

Green building practices include high-performance insulation, efficient HVAC systems, renewable energy, water-saving fixtures, and sustainable materials. Orientation and shading reduce cooling loads. Daylighting reduces electric lighting. Rainwater harvesting and greywater systems cut water use.

Certification programs like LEED, BREEAM, and Passive House provide frameworks and benchmarks. They vary in rigor and emphasis, but they all push designers to measure performance rather than assume it.

Green building is not just about technology. It is also about behavior and operations. A building designed to be efficient will not perform well if occupants and managers do not use it as intended. Commissioning and monitoring matter.

The field is evolving. Net-zero buildings, carbon-neutral construction, and regenerative design are pushing the boundaries further.