The home environment can have a profound influence on health and well-being. Homes with poor structural and environmental conditions can contribute to a host of illnesses and medical symptoms for residents. Poorly sealed building envelopes can allow in pests, excess moisture, air pollution, and other stressors that can cause or exacerbate health problems. More than half of the U.S. building stock is over 35 years old, and, in some cases, these older buildings were constructed with hazardous materials such as lead and asbestos. Older homes are also more likely than newer ones to contain malfunctioning building systems and equipment due to natural degradation and increased chances of deferred maintenance over time.
Measures that improve energy efficiency can also make homes safer and healthier. Energy efficiency can improve indoor temperature control (particularly important during power outages), reduce exposure to air pollution, and strengthen the financial security of families by lowering energy bills and healthcare costs. Energy-efficient buildings are sealed (and ventilated) to prevent ambient air pollution and excessive moisture from entering through cracks in attics, basements, windows, and other openings. Residential energy efficiency programs frequently address air penetration around windows as part of measures to seal the building envelope. Because energy-efficient buildings are well insulated, climate-controlled air stays at a temperature that is comfortable for occupants throughout. Enhanced ventilation can improve the indoor environment, reducing airborne contaminants such as particulate matter, mold, and pest droppings. Some energy efficiency programs also address basic safety concerns such as smoke, radon, and carbon monoxide detectors and handrails. These measures save lives. Changes to the living environment can mitigate allergies as well as the symptoms of other respiratory illnesses such as chronic obstructive pulmonary disease (COPD) and asthma.