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Framing Materials

ENERGY STAR certified windows come in a variety of framing materials.

  • Fiberglass frames are strong, durable, low maintenance, and provide good insulation. Fiberglass frames can be either hollow or filled with foam insulation.
  • Vinyl frames are low maintenance and provide good thermal insulation. Sections may be hollow or filled with foam insulation. Wide vinyl sills may be reinforced with metal or wood.
  • Aluminum frames are durable, low maintenance, recyclable, and typically have at least 15% recycled content. Frame design typically includes thermal breaks to reduce conductive heat loss through the metal.
  • Wood frames are strong, provide good insulation, and are generally favored in historical neighborhoods. The exterior surfaces of many wood windows are clad (or covered) with aluminum or vinyl to reduce maintenance.
  • Combination frames use different materials separately throughout the frame and sash to provide optimal performance. For example, the exterior half of a frame could be vinyl while the interior half could be wood.
  • Composite frames are made of various materials that have been blended together through manufacturing processes to create durable, low maintenance,well-insulated windows.


ENERGY STAR is a U.S. Environmental Protection Agency (EPA) voluntary program that helps businesses and individuals save money and protect our climate through superior energy efficiency.

The ENERGY STAR program was established by EPA in 1992, under the authority of the Clean Air Act Section 103(g). Section103(g) of the Clean Air Act directs the Administrator to “conduct a basic engineering research and technology program to develop, evaluate, and demonstrate non–regulatory strategies and technologies for reducing air pollution.” In 2005, Congress enacted the Energy Policy Act. Section 131 of the Act amends Section 324 (42 USC 6294) of the Energy Policy and Conservation Act, and “established at the Department of Energy and the Environmental Protection Agency a voluntary program to identify and promote energy–efficient products and buildings in order to reduce energy consumption, improve energy security, and reduce pollution through voluntary labeling of or other forms of communication about products and buildings that meet the highest energy efficiency standards.” Under EPA’s leadership, American consumers, businesses, and organizations have made investments in energy efficiency that are transforming the market for efficient products and practices, creating jobs, and stimulating the economy. Now in its 23rd year, the ENERGY STAR program has boosted the adoption of energy efficient products, practices, and services through valuable partnerships, objective measurement tools, and consumer education.

Building Envelope

Installing Replacement Windows

Windows play a major role in the energy use and comfort of a dwelling unit. In the winter, heat in a room is lost when cold outside air infiltrates around the edges of windows. Heat also can be lost by conduction directly through the pane, even if the window fits tightly. The cold drafts and the chilly windowpane make the room uncomfortable. But windows also can help to heat a room by letting the sun’s rays enter. While this solar radiation is beneficial in the winter, it can be a major source of

discomfort in hot, summer climates.


  • Single-family and multifamily buildings whose windows need replaced due to deterioration
  • Buildings in which residents control the heating


  • Double- and triple-pane
  • Inert gas-filled
  • Coated


  • Some windows (e.g., casements) cannot readily be equipped with storm windows.


  • Replacing poor-quality windows can save 10 to 20 percent on heating energy.
  • If the existing heating system is not adequately controlled, no savings will occur because residents will have to open their windows for relief from overheating.

Energy Star

ENERGY STAR is a voluntary labeling program designed to identify and promote energy-efficient products. ENERGY STAR-labeled products save energy and money while protecting the environment. Improving energy efficiency in HUD-financed and HUD-assisted housing can generate significant savings for property owners and building residents.

Products can earn the ENERGY STAR in a variety of categories including:

  • Appliances
  • Lighting
  • Windows and Doors
  • Heating and Cooling
  • Room Air Cleaners
  • Exit Signs
  • Office Equipment
  • Electronics

Bulk Purchasing

HUD encourages housing authorities, managers of assisted housing and other grantees to purchase ENERGY STAR qualified equipment. The ENERGY STAR Online Bulk Purchasing Tool—developed by the U.S. Department of Energy, in collaboration with the U.S. Department of Housing and Urban Development and the U.S. Environmental Protection Agency—makes it easy to comparison shop for energy-efficient products. The tool provides a simple way to obtain bids on ENERGY STAR qualified products such as appliances, compact fluorescent light bulbs, and light fixtures.

New homes can earn the ENERGY STAR though the ENERGY STAR New Homes program, which uses strict energy-efficiency guidelines set forth by EPA. The ENERGY STAR Website also identifies ways to make your home or business more energyefficient, and thus less costly to operate. For example, the Small Business section includes resources to reduce energy use. The Solutions to Common Home Improvements section helps resolve energy issues in existing homes and offers advice on increasing energy-efficiency levels during a remodeling project.

How is HUD involved with ENERGY STAR?

HUD, EPA, and DOE signed a formal partnership in 2002 to promote ENERGY STAR throughout HUD’s affordable housing programs. Efforts to promote ENERGY STAR will not only improve the energy-efficiency of the affordable housing stock, but will also help protect the environment.

Increasing energy-efficiency in the public housing stock can yield significant cost savings for property owners and building residents. EPA estimates that an individual apartment renter can save 15% to 20% with the installation of ENERGY STAR qualified products such as refrigerators, window air-conditioners, and lighting. A new home that has earned the ENERGY STAR can save 30% or more on heating and cooling bills. This can be a savings of $200 to $400 a year.

HUD issued a notice in July of 2005 that encourages ENERGY STAR as the standard for Public Housing Agencies (PHAs), encourages PHAs to implement energy saving activities, and informs PHAs that ENERGY STAR expertise is available to provide valuable assistance for implementing energy conservation initiatives.

Other Federal Programs

HUD Rehabilitation Energy Guidelines

One easy-to-use source for finding cost-effective ways to remodel an existing building is HUD’s Energy Efficient Rehab Advisor. The Rehab Advisor’s energy-efficiency recommendations are based on ENERGY STAR specifications, where applicable.

PATH (Partnership for Advancing Technology in Housing)

This public-private partnership seeks to improve housing affordability and value through technology. The PATH Website contains a wealth of tools and information to help you to integrate advanced housing technologies into your project.

Rebuild America

A voluntary DOE program that helps community partnerships make profitable investments in existing buildings through energy-efficiency technologies. Partnerships tailor their programs to local needs, choosing which buildings to renovate, how much energy to save, and the best technologies to use. Rebuild America focuses on several areas, including public and multi-family housing. In addition, State Energy Program (SEP) supports the work of state energy offices to increase the energy efficiency of residential buildings.


Energy Conservation for Housing – A Workbook, HUD, September 1998. Pages 7-9 through 7-12 address energy saving storm windows.

HUD Energy Efficient Rehab Advisor. Discusses selection of windows, skylights, and doors.

Selecting New Energy-Efficient Widnows. Part of the U.S. Department of Energy’s Consumer’s Guide.

Improving Energy Efficiency in Apartment Buildings, American Council for an Energy-Efficient Economy, 1995. ISBN 0-918249-23-6. Pages 90 through 95 address window energy efficiency.

ENERGY STAR® Windows. A partnership between the U.S. Department of Energy and manufacturers of windows, doors, and skylights. Addresses energy-efficient windows, applications, and more.

Efficient Windows Collaborative. Addresses windows and efficiency, including fact sheets to help select windows by location.

Selecting Windows for Energy Efficiency. A more detailed Lawrence Berkeley Laboratory publication that discusses energy-related characteristics of windows, energy performance ratings, selection guidelines.

National Fenestration Rating Council. Provides consistent ratings on window, door and skylight products.