ELI5: Explain Like I'm 5

Zero-energy building

A zero-energy building is a building that produces as much energy as it uses. It does this by using solar panels or other renewable energy sources to produce its own energy. It also uses energy-efficient windows, insulation, and other measures to make sure it's using as little energy as possible. It's like a house that pays for itself over time because it'll save money on electricity bills.