Weatherization

Did You Know?

There are tax incentives available for improving the energy efficiency of your historic building. Not only could your project qualify for a historic preservation tax credit, but it may also be eligible for federal income tax incentives for energy efficiency. Learn more about these credits from the non-profit Tax Incentives Assistance Project.

Conduct an Energy Audit

An energy audit should be undertaken before energy-improvement measures are implemented. The audit evaluates the building’s current thermal performance and identifies any deficiencies in the building envelope or mechanical systems. Local utilities may offer simple audits at no cost or more in-depth audits for a reasonable fee.

door blower test in action

The blower door test is a standardized diagnostic tool that measures the air tightness of a building envelope.

The energy audit measures the R-value of various components of the building envelope including walls, ceilings, floors, doors, windows, and skylights. The R-value is a construction industry standard of measurement of resistance to thermal transfer, commonly known as heat loss; the higher the number, the better the resistance is to heat loss. The audit also includes inspection of the building envelope to identify areas of air infiltration. Tools such as a blower door test blower door test or infrared thermography may be used to identify specific areas of infiltration, lack of insulation or thermal bridging. The type and age of mechanical systems and major appliances are also recorded.

The results of the energy audit will identify current deficiencies in the building and will help you select the most cost-effective remedial measures, such as added insulation, caulking, lighting improvements, and repair or replacement of mechanical systems or major appliances. Once you diagnose where problems exist you can determine which improvements will be the most cost effective and will provide the maximum comfort and energy savings.

Find more information about home energy audits at Energy Star or learn how to perform a simple energy audit yourself.

Do-It-Yourself Home Energy Audit

Excerpted from Energy Savers, Energy Efficieny and Renewable Energy, U. S. Department of Energy

You can easily conduct a home energy audit yourself. With a simple but diligent walk-through, you can spot many problems in any type of house. When auditing your home, keep a checklist of areas you have inspected and problems you found. This list will help you prioritize your energy efficiency upgrades.

Locating Air Leaks

First, make a list of obvious air leaks or drafts. The potential energy savings from reducing drafts in a home may range from 5% to 30% per year, and the home is generally much more comfortable afterward. Check for indoor air leaks, such as gaps along the baseboard or edge of the flooring and at junctures of the walls and ceiling.

Check to see if air can flow through these places:

  • Electrical outlets
  • Switch plates
  • Window frames
  • Baseboards
  • Weather stripping around doors
  • Fireplace dampers
  • Attic hatches
  • Wall or window-mounted air conditioners

Also look for gaps around pipes and wires, electrical outlets, foundation seals, and mail slots. Check to see if the caulking and weather stripping are applied properly, leaving no gaps or cracks, and are in good condition.

Inspect windows and doors for air leaks. See if you can rattle them, since movement means possible air leaks. If you can see daylight around a door or window frame, then the door or window leaks. You can usually seal these leaks by caulking or weather stripping them. Check the storm windows to see if they fit and are not broken.

If you are having difficulty locating leaks, you may want to conduct a basic building pressurization test:

  1. First, close all exterior doors, windows, and fireplace flues.
  2. Turn off all combustion appliances such as gas burning furnaces and water heaters.
  3. Then turn on all exhaust fans (generally located in the kitchen and bathrooms) or use a large window fan to suck the air out of the rooms.

This test increases infiltration through cracks and leaks, making them easier to detect. You can use incense sticks or your damp hand to locate these leaks. If you use incense sticks, moving air will cause the smoke to waver, and if you use your damp hand, any drafts will feel cool to your hand.

On the outside of your house, inspect all areas where two different building materials meet, including:

  • All exterior corners
  • Where siding and chimneys meet
  • Areas where the foundation and the bottom of exterior brick or siding meet

You should plug and caulk holes or penetrations for faucets, pipes, electric outlets, and wiring. Look for cracks and holes in the mortar, foundation, and siding, and seal them with the appropriate material. Check the exterior caulking around doors and windows, and see whether exterior storm doors and primary doors seal tightly.

When sealing any home, you must always be aware of the danger of indoor air pollution and combustion appliance “backdrafts.” Backdrafting is when the various combustion appliances and exhaust fans in the home compete for air. An exhaust fan may pull the combustion gases back into the living space. This can obviously create a very dangerous and unhealthy situation in the home.

In homes where a fuel is burned (i.e., natural gas, fuel oil, propane, or wood) for heating, be certain the appliance has an adequate air supply. Generally, one square inch of vent opening is required for each 1,000 Btu of appliance input heat. When in doubt, contact your local utility company, energy professional, or ventilation contractor.

Insulation

Heat loss through the ceiling and walls in your home could be very large if the insulation levels are less than the recommended minimum. When your house was built, the builder likely installed the amount of insulation recommended at that time. Given today's energy prices (and future prices that will probably be higher), the level of insulation might be inadequate, especially if you have an older home.

If the attic hatch is located above a conditioned space, check to see if it is at least as heavily insulated as the attic, is weather stripped, and closes tightly. In the attic, determine whether openings for items such as pipes, ductwork, and chimneys are sealed. Seal any gaps with an expanding foam caulk or some other permanent sealant.

While you are inspecting the attic, check to see if there is a vapor barrier under the attic insulation. The vapor barrier might be tarpaper, Kraft paper attached to fiberglass batts, or a plastic sheet. If there does not appear to be a vapor barrier, you might consider painting the interior ceilings with vapor barrier paint. This reduces the amount of water vapor that can pass through the ceiling. Large amounts of moisture can reduce the effectiveness of insulation and promote structural damage.

Make sure that the attic vents are not blocked by insulation. You also should seal any electrical boxes in the ceiling with flexible caulk (from the living room side or attic side) and cover the entire attic floor with at least the current recommended amount of insulation.

If your basement is unheated, determine whether there is insulation under the living area flooring. In most areas of the country, an R-value of 25 is the recommended minimum level of insulation. The insulation at the top of the foundation wall and first floor perimeter should have an R-value of 19 or greater. If the basement is heated, the foundation walls should be insulated to at least R-19. Your water heater, hot water pipes, and furnace ducts should all be insulated. For more information, see Install insulation.

Heating/Cooling Equipment

Inspect heating and cooling equipment annually, or as recommended by the manufacturer. If you have a forced-air furnace, check your filters and replace them as needed. Generally, you should change them about once every month or two, especially during periods of high usage. Have a professional check and clean your equipment once a year.

If the unit is more than 15 years old, you should consider replacing your system with one of the newer, energy-efficient units. A new unit would greatly reduce your energy consumption, especially if the existing equipment is in poor condition. Check your ductwork for dirt streaks, especially near seams. These indicate air leaks, and they should be sealed with a duct mastic. Insulate any ducts or pipes that travel through unheated spaces. An insulation R-Value of 6 is the recommended minimum.