For instance, carpets are made from recycled plastic bottles, insulation from recycled newspapers, and outdoor decking from plastic grocery bags. The toxicity of building materials is another concern. Some materials, such as polyvinyl chloride plastic, are made from chemicals that create pollution during various stages of their life-cycle, from extraction to manufacturing to disposal. Other materials off-gas chemicals to which some people are allergic or sensitive. Energy Conventional non-renewable forms of energy production and energy use are major spoilers of the environment through pollution, habitat loss and carbon dioxide emissions.
Any energy saved is an environmental benefit.
En-houses find ways to use natural energy flows such as sunlight, wind and water, and to use electricity and heating gas efficiently. Using the sun as it shines is living on current solar income instead of using up our limited fossil fuel reserves. As in business or household finance, it is sustainable to live off current income instead of constantly dipping into capital reserves that will become more expensive and someday run out. Active solar systems use machines to convert sunlight into electricity or heat and transmit this energy so that it can be used by systems in the building. An example of an active solar system is a solar hot water heater, which uses the sun to heat water directly.