Passive Building Strategies.
Passive design strategies utilize what nature provides for free to keep buildings comfortable without the need for purchased energy. Passive strategies are integrated strategically into the design of a building to work with natural elements on a building site (including sun and wind patterns) to provide free heating and cooling of spaces through different seasons.
Active Building Strategies.
Active design strategies use purchased energy (including electricity and natural gas) to keep buildings comfortable. These strategies include mechanical system components such as air-conditioning, heat pumps, radiant heating, heat recovery ventilators, and electric lighting. Active strategies also include systems that generate energy such as solar electric and solar thermal panels, wind turbines, and geothermal energy exchangers.