Building Envelope

Information about the parts of a house that separates the outdoors from the indoors, including information about insulation, air-sealing, windows, and doors.

Energy Audits and Home Performance

How Well Does Your Home Function?

Many homes don't perform as well as they could, but sorting out the causes from the symptoms can sometimes be confusing, and deciding how to prioritize the list of projects can make any homeowner frustrated. In order to best determine what is really going on with your house (and the most effective way of addressing it) you may require the expertise of a home performance consultant. Home performance consultants (sometimes called home auditors) evaluate the operation of various components of your home, and can help assess the need for a variety of home improvements including energy efficiency improvements, remodeling projects, or even constructing a new home.

Although any home, new or old, can benefit from diagnostic services, they are most useful when you are:

• Experiencing high or erratic utility bills.
• Having problems with drafts, cold spots, frosty windows, or other comfort concerns.
• Experiencing mold, mildew, or chronic moisture issues.
• Having ice dams, icicles, or other roof and attic problems.
• Planning a remodeling project or investing in any major home improvement, such as new windows, siding, or insulating.
• Replacing a major appliance, such as a furnace, air conditioner, or water heater.
• Considering the installation of mechanical ventilation.
• Building a new home.

Home performance testing consists of a comprehensive energy-related evaluation of your home. This service can include many components:

• On-site evaluation of your home.
• Safety testing of combustion equipment, including carbon monoxide testing, inspection of chimney vent piping, insuring proper draft of combustible gas appliances, performing a "worst case" draft test.
• Inspection of mechanical systems, including heating, cooling, water heating, and ventilation systems.
• Inspection of insulation types, levels and values for walls, attics, crawlspaces, windows, etc.
• Blower door testing to measure air tightness.
• Measurement of room pressures (forced air systems only).
• Measuring exhaust fan flow rates.
• An infrared thermal scan with an infrared camera to measure temperature changes within a home's building shell in order to determine voids in insulation or air leaks.
• Duct leakage testing to measure the amount of air leakage within a forced air heating or cooling ductwork system.
• Home Energy Rating System (HERS) is a computer analysis report that generates a Home Energy Rating System score. A HERS inspection and rating score is used by the mortgage industry to assist in prioritizing energy efficiency projects for existing homes.

Once the current operation of your house has been assessed, the home performance consultant will make recommendations for repairs, maintenance, or additional products or services, and will help you to prioritize which measures should be taken first. After any repairs, installations, or other work is completed, you may want to have the home performance consultant re-inspect to verify that everything was completed fully and correctly.

Home performance consultants can be located through your utility provider or through the Minnesota Building Performance Association. MBPA is a non-profit organization committed to promoting high quality, energy efficient home improvements on existing homes and efficient construction of new homes. The home performance consultants of MBPA are independent technicians who do not sell any energy product or equipment and have extensive training in energy related topics, knowledge of building science, and adhere to the "house as a system" approach to energy improvements.

For more information, visit our website or call 800-657-3710 or 651-539-1886.

Radiant Barriers and Attics

The Minnesota Department of Commerce, Division of Energy Resources (DER), has received several questions from Minnesota residents regarding the purchase and installation of radiant barriers in attics. Vendors of this technology are pitching their products to consumers in mailers and inviting them to presentations to learn more. Consumers, in turn, are looking to DER for guidance.

DER encourages consumers to conduct careful and thorough research before investing in any energy-efficiency technology or improvement for their home. The benefits associated with many such products can vary depending on a number of factors, including the unique characteristics of a consumer's home and the climate in which the consumer resides.

Radiant barriers consist of a reflective film installed over the top of attic insulation in existing homes. They are sold as an energy-saving product, with claims of significant reductions in both heating and cooling costs. An Oak Ridge National Laboratory study concludes that attic radiant barriers are not an effective way to reduce heating or cooling loads in Minnesota. The test further concludes that adding conventional attic insulation would be a much better option for saving energy. In fact, as the attic insulation level increases, the study says, the potential benefits from a radiant barrier decrease.

For more information on insulation and other energy-efficient measures to improve your home, contact us at 800-657-3710 or 651-539-1886. Find free downloadable home energy guides, including "Home Insulation" and "Home Envelope."