Net-zero energy buildings start with energy-conscious design. Many features work without an energy source. For example, in cold climates, south-facing buildings with large expanses of windows on that side can produce well over 50% of their heat through passive solar gain. On the cold north side of the building, smaller windows can angle to wider openings, permitting more light while limiting heat loss.
In warmer seasons, passive ventilation systems can pull cool air up from the lower levels and vent it through the building’s highest point. Rooftop systems can collect rainwater to reduce usage of treated water. Solar panels, heat recovery systems, geothermal heating and wind turbines are among the other technologies used to achieve net-zero status.