) or weatherproofing
) is the practice of protecting a building and its interior from the elements, particularly from sunlight
, and wind
, and of modifying a building to reduce energy consumption and optimize energy efficiency
Weatherization is distinct from building insulation, although building insulation requires weatherization for proper functioning. Many types of insulation can be thought of as weatherization, because they block drafts or protect from cold winds. Whereas insulation primarily reduces conductive heat flow, weatherization primarily reduces convective heat flow.
In the United States, buildings use one third of all energy consumed and two thirds of all electricity. Additionally, they are a major source of the pollution that causes urban air quality problems and pollutants that contribute to climate change. Buildings account for 49 percent of sulfur dioxide emissions, 25 percent of nitrous oxide emissions, and 10 percent of particulate emissions.
Typical weatherization procedures include:
- Sealing bypasses (cracks, gaps, holes), especially around doors, windows, pipes that penetrate the attic ceiling, and other areas with high potential for heat loss, using caulk, foam sealant, weather-stripping, window film, door sweeps, electrical receptacle gaskets, and so on to reduce infiltration.
- Protecting pipes from corrosion and freezing.
- Installing footing drains, foundation waterproofing membranes, interior perimeter drains, sump pump, gutters, downspout extensions, downward-sloping grading, French drains, swales, and other techniques to protect a building from both surface water and ground water.
- Providing proper ventilation to unconditioned spaces to protect a building from the effects of condensation. See Ventilation issues in houses
- Installing roofing, building wrap, siding, flashing, skylights or solar tubes and making sure they are in good condition on an existing building.
- Installing insulation in walls, floors, and ceilings, around ducts and pipes, around water heaters, and near the foundation and sill.
- Installing storm doors and storm windows.
- Replacing old drafty doors with tightly sealing, foam-core doors.
- Replacing older windows with low-energy, double-glazed windows.
The phrase "whole-house weatherization" extends the traditional definition of weatherization to include installation of modern, energy-saving heating and cooling equipment, or repair of old, inefficient equipment (furnaces, boilers, water heaters, programmable thermostats, air conditioners, and so on). The "Whole-House" approach also looks at how the house performs as a system.
US Weatherization Assistance Program
Weatherization has become increasingly high-profile as the cost of home heating has risen. The US Weatherization Assistance Program (WAP) was created in 1976 to help poverty
families reduce energy consumption and costs. WAP reaches across all fifty states, the District of Columbia, and Native American tribes. The goal of WAP is to assist low-income families by reducing energy bills and decrease dependency on foreign oil
by decreasing energy use
The US Department of Energy estimates that over 5.6 million homes have been weatherized, saving 30.5 million MBtu of energy each year. It estimates weatherization returns $2.69 for each dollar spent on the program, realized in energy and non-energy benefits. Families whose homes are weatherized are expected to save $358 on their first year's utility bills.
Many state LIHEAP (Low Income Home Energy Assistance) programs work side by side with WAP to provide both immediate and long term solutions to energy poverty.