• Add insulation to the attic, walls and/or floors. If insulation is added, holes may be drilled in the siding and vents may be added to the roof. RESULT: The amount of heat loss through the walls, ceilings and floors will be reduced.
• Perform an efficiency inspection on natural gas, propane and fuel oil furnaces, boilers and water heaters. RESULT: More heat will be gained from the same amount of fuel used.
• Replace broken glass in primary windows. RESULT: The amount of cold air coming in will be reduced.
• Install or adjust door weatherstripping, thresholds, and/or door sweeps. RESULT: The amount of cold air coming in will be reduced.
  

• An increase in comfort — reduced drafts and a more even temperature throughout your home.
• Your heating and cooling bills should be reduced.
• You should need less energy to heat and cool your home.

Weatherization: What to Expect
Many weatherization service providers utilize "whole house weatherization." Under this approach, providers evaluate the house as a single energy-consuming system, rather than a loose collection of unrelated systems. This approach finds the best combination of methods for reducing total energy consumption in a house.

Air Leakage Control
Reducing the leakage of cold outside air into the house in winter — or hot outside air in the summer — is the most common type of weatherization improvement made in a home. Typically, work crews add caulking and weather stripping around windows and doors to reduce drafts. Old, drafty homes are not only uncomfortable, but they are also very costly to heat and cool.

Tests using blower doors reveal more precisely the holes in the building envelope where outside air infiltrates into the house. Such holes often occur near the base of the building and near the roof and are unobservable to the naked eye.

With the readings from the gauges and house volume calculations, how well a home is ventilated can be determined. At this point, technicians walk around and look for the leaks in the building envelope. Sealing leaks to the exterior of the home — and blower door testing after the leaks have been sealed — will quantify the results and assess the need for additional sealing.

Insulation
Making sure there is enough insulation in the walls, foundation and roof — anywhere there is a barrier between the home and the outside — is one of the most important ways to make a home energy efficient. As a result, insulation is a part of almost every weatherization project.

Installing insulation with a uniform coverage and density is very important because the wall cavities are like chimneys. Air leakage can greatly reduce insulation’s thermal performance. The installer must inspect walls for structural soundness of the home before any insulation is added.

A safety inspection of the heating system is performed first, including:

• Test for carbon monoxide in the air in the living space and in the combustion appliance zone.
• Check for fuel leaks using a combustible gas detector.
• Inspect the wiring to the appliance.
• Check the vent connections and clearances.
• Inspect for safety devices

A combustion test is performed to collect information on safety and efficiency. The system is also tested to make sure it does not backdraft in adverse conditions, such as when all the ventilation fans are operating in the house. Fans can have an impact on the how well a heating system vents.