What is Energy Star?

Energy Star / The basics

What is Energy Star?

Energy Star is a voluntary program created by the US Environmental Protection Agency ( EPA ). The program is managed by the EPA together with the Department of Energy ( DOE ). The object of the program is to assist consumers, individuals and businesses to make informed decisions on energy saving methods, products and efficiencies. The Energy Star label is a recognized symbol for energy efficiency and can be found within product specifications, new homes, commercial structures as well as industrial plants.

A partnership with the Energy Star program will assist in energy conservation as well as the “best practice “methodology of construction.

The Energy Star program was started by the EPA in 1992 and operates under the authority of the Clean Air Act, as well as the 2005 Energy Policy Act. It is estimated that the Energy Star program has saved upwards of 400 billion dollars on more efficient energy consumption, as well as reducing the negative emissions of mechanical systems.

Originally initiated as a voluntary labeling process to identify and promote energy efficient products, the Energy Star program has grown to involve construction techniques, labeling of appliances as well as mechanical systems, insulation standards as well as the “ best practice “ methodology of moisture protection, in efforts to eliminate the growth of mold and mildew.

The Energy Star program currently employs nearly 300,000 different types of workers that are involved in the consulting of the programs, as well as the manufacture of Energy Star products and methodologies.

This discussion will focus on the various Energy Star requirements for new residential construction. The Energy Star methodology has extended considerably into industrial and manufacturing plants as well as educational and healthcare facilities.

Specifics for each application of the Energy Star objectives can be researched under the Energy Star website.

Basic residential home Energy Star information

  • Insulation: Insulation is measured by what is identified as an R value. Each product that is used to assemble a wall, ceiling, roof, etc. has a specific R value. For example the fiberglass insulation that is installed within any assembly has an R value. However, the other elements of that assembly also have an R value. The total combination of the all of the elements that are required, to construct an assembly, will identify the total R value of the walls, ceilings, or other areas of construction that is being considered. Each area of the country has different R values that are recommended by the Energy Star program. These R values should be investigated, based upon your location on the website.
  • Vapor barrier: The vapor barrier is the membrane or barrier that keeps the insulation from becoming wet or damp due to condensation.   Condensation or moisture build-up, occurs when warmer air, that has the capability of holding moisture, is cooled down or is subjected to a cooler surface. The layer of warmer air that is cooled, or comes into contact with the cooler surface becomes less capable of holding the moisture within it, due to the dropping temperature. This moisture must dissipate out of the cooling air and will collect as water droplets on an adjacent surface, or accumulate at the bottom of this surface, as gravity causes the water to drip down. This collection of water could cause mold and mildew to grow and flourish due to the fact that it is accumulating in an enclosed environment, without the ability to vaporize or dry out. This moisture provides a perfect environment for mold growth.

Due to this physical dissipation of water, from warmer air to cooler air, the concept of a vapor barrier was introduced.

Initially plastic was thought to be the perfect barrier to prevent transmission of moisture. Through the years of environmental development and improvements, it has been found, that the total and complete impermeability of plastic, was not providing the proper protection for water accumulation. Incorrect placement of the vapor barrier was resulting in soaking wet walls and water accumulation at the base of walls and in ceiling assemblies. This accumulation of water promoted mold growth and caused health issues and problems.

The current recommendation is a vapor barrier that is somewhat breathable where air can actually penetrate the medium. In this manner, there is the ability of any moisture accumulation, to actually dissipate as vapor, or dry out, and not simply accumulate.

Many Energy Star consultants are now recommending that the insulation within the walls be installed without a vapor barrier. If fiberglass batts are being used, the current recommendation is that the batts be installed without a kraft paper surface. The current recommendation is to paint the drywall that is used to cover the uncovered fiberglass batts with vapor barrier paint, which will diminish the transfer of moisture, but not provide the total and complete impermeable air seal, that other types of vapor barriers had provided. The placement of the vapor barrier, due to potentially damaging issues if placed in the wrong location within the assembly should be carefully designed and installed.

This placement of a vapor barrier is extremely important, and any Energy Star consultant will explain the details, and the proper construction and placement of this extremely important element of the insulation system.


  • Flashing details: Various flashing details are important to securing a high level of Energy Star rating points. Each specific detail can be found on the website; however basic understanding of flashing performance will allow you to make sense of the Energy Star requirements.


  • Window and door flashings: it is important that all windows and doors are installed against a continuous, impermeable flashing membrane, installed at the head and jambs of the opening. The head is the top of the opening, and the jambs are the sides of the openings. In the past, a strip of 15 lb. felt was installed on the face of the sheathing around the window, on all four sides of the opening. The window would be installed with the mounting flanges tight against the felt paper. Another layer of felt would then be placed over the perimeter flanges to prevent water from penetrating into the window’s rough opening. In today’s more contemporary building, there are several different specific tapes and products that are specifically designed to self-adhere to the sheathing, and seal the opening from moisture. These special products are easily searched on the internet and are available at all hardware and building supply stores.


  • The sill of the window and doors are treated in a different manner than the head and the jambs. Due to the importance of the base of both installations due to water accumulation, the flashings at the sill in both instances, is much more important and advanced. Any water that leaks down to the sills of either windows or doors should be allowed to make its way out into the atmosphere. This is accomplished by the installation of the proper type of flashings as well as the elimination of a full seal along the sill level. It is recommended that the caulking seal at the bottom of the sill be intermittent to allow areas for any water accumulation to discharge or run out to the atmosphere. Remember the objective is to keep the water out of the system, however, if water should get into the assembly, either door or window, it must be allowed to drain out.


  • Ventilation: The importance of proper ventilation is paramount in following the Energy Star guidelines and requirements. Ventilation is important for energy efficiency, as well as proper maintenance of insulation assemblies and the overall health of the structure.

Ventilation within the upper attic spaces is especially important to maintain the temperature within the home, and to properly rid the attic space of accumulated moisture. Gable end venting, soffit venting and ridge venting are methods of properly venting the attic spaces within the home or commercial structure. Dependent upon the area of the country that the structure is being built will determine the amount of venting required.

It is recommended that a professional Energy Star Consultant be contacted to determine by calculations, the proper amount of venting that is required based upon the type of construction, the mechanical methods of heating and cooling within the structure as well as the location of the structure.

Ventilation, similar to the proper placement of the vapor barrier, has been found to be as important, or in some instances, more important than the type, and amount of insulation used within the structure.

  • Mechanical and electrical equipment used within the home; The use of proper Energy Star equipment is essential to maintaining the Energy Star rating of the structure. As with many other types of testing and government agencies, the actual physical benefits of an Energy Star rating will be argued and discussed forever. However, to qualify for an Energy Star rating, it is mandatory that Energy Star appliances, as well as mechanical and electrical equipment be utilized. The cost of these Energy Star products in some instances appears excessive; however their use is necessary to fulfill the requirements. Additional commentary is left for you the consumer, regarding the financial balance of the Energy Star rating and the additional cost of the equipment.


  • Continual ventilation within the residential envelope; The Energy Star rating requires the use of a continuous ventilation of the interior residential envelope. This continuous ventilation is accomplished by the use of either a kitchen fan, bathroom fan or other mechanical device that will continually move the air within the inhabited areas. For example, the use of a continually running ventilation fan within the bathroom will provide the required air changes that will be necessary to accommodate the Energy Star requirements. In most situations, these types of fans will have a manual switch, which will increase the amount of cubic feet of air movement for actual bathroom ventilation use. A normal Energy Star bathroom fan, for example will run continuously at 30 cubic feet per minute and have a switch that will push the fan speed to 90 cubic feet a minute for actual bathroom ventilation purposes.


  • Sealing of interior surfaces; Energy Star requirements, limit that amount of air that can be lost within a residential unit. The normal allowance is .25 cubic feet of air per square foot of surface. Therefore in a normal residential unit of 1500 SF, there is normally approximately 4500 SF of wall, ceiling and floor surface. If this is the case then the actual allowed loss of air during a test would be .25 cubic feet time the 4500 SF of surface area. Based upon this requirement, it is essential that the bottom and top of all the interior sheathing surfaces be sealed with a sealant, to prevent the movement of air into the interior of the wall, ceiling and floor assemblies. In most situations, this sealing is accomplished by placing the sheathing directly down onto a bead of sealant, which is applied on the floor, ceiling or wherever the next piece of sheathing is installed.


The use of the Energy Star rating system will allow you to construct a home that will comply with the Energy Star requirements. In some instances there is a substantial tax or energy credit that can be applied to the residential structure.

It is recommended that an Energy Star Consultant be contacted and used, if this type of construction is being considered.




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