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Permanent Window Labels

The permanent labels allows 1) manufacturer and product information and 20 the performance rating to be tracked for the life of the fenestration product. These labels are placed on certified products and are usually affixed on and interior part of the product between the frame and sash or the frame and door. The label should be visible after the products have been installed. Three types of permanent labels can be found on fenestration: AAMA, NWWDA or NAMI

AAMA Labels

The American Architectural Manufacturers Association (AAMA) certification label serves the purpose of identifying fenestration products that conform within specific tolerances. The design and fabrication of fenestration models are tested in accordance with the procedures established by the AAMA Certification program and have met the requirements of the specification printed on the label. The fenestration products include windows, doors and skylights manufactured from aluminum, vinyl, fiberglass, composites and a combination of these materials with wood.

AAMA certification is third party certification. The third party is and outside organization not under the control of influence of AAMA. This third party is responsible for the validation and administrative functions for the program.

AAMA accredits independent third party laboratories that test the performance of the manufacturer's products. The most important function of certification is the assurance that products bearing the label do, in fact, meet the requirements of the standard. AAMA rates the window's ability to withstand wind loads, water resistance and the air infiltration rate. The higher the grade the better the window's performance.

Product Designation

AAMA certified window and door products are designated by a four-part code, which includes product type, performance class, performance grade, and maximum size tested. A typical code will look like this: 

HS - R - 25 - 48x76

In this example, HS is the product type, R is the performance class, 25 the performance grade and 48x76 the maximum size tested (width x height).

Product Type

The AAMA permanent labels are placed on sixteen different window product types. These products type designations and the abbreviated forms are shown below.

VS = Awning, Hopper or Projected Windows
= Basement Windows
= Casement Windows
= Dual Action Windows
= Dual Action Hinged Glass Doors
= Fixed Windows
= Greenhouse Windows
= Hung Windows (Single, Double, Triple)
= Hinged Egress
= Hinged Glass Doors
= Horizontal Sliding Windows
= Jalousie Windows
= Jal-Awning Windows
= Side Hinged Inswing Windows
= Tropical Awning Windows
= Top Hinged Windows
= Vertically Pivoted Windows
= Vertical Sliding Windows

Performance Class

The AAMA permanent labels are affixed the five different classes of window and door products shown below.

AW = Residential
= Light Commercial
= Commercial
= Heavy Commercial
= Architectural

Performance Grade

Performance is designated by a number which follows the type and class designation. For example, Double-Hung Residential window may be designated HR15. The number establishes the design pressure, in this case 15 psf. The structural test pressure for all windows and doors is 50% higher than the design pressure which, for the example HR15 window, would have been successfully tested at 22/.5 psf structural test pressure.

Minumum design pressure, structural test pressure, and water resistance test pressures for the five classes in pounds per square foot are shown below.

Window and Door Classes Design Pressure Structural Test
Pressure Water Resistance
Test Pressure Residential
Light Commercial
Heavy Commercial
Architectural 15
40 22.5
60.0 2.86


The National Wood Window and Door Association (NWWDA) has for many years been active in millwork product research. The primary function of this research has been to develop industry standards and certification programs for wood windows, doors and skylights.

Participation in the NWWDA certification program is available to all manufacturers and distributor who qualify. Each participant must prove, by meeting rigid specifications, inspections and tests that their products meets the criteria of the NWWDA industry standards. In order to insure continued conformance, a program of periodic in-plant inspections and testing is maintained.

In this manner, architects, builders, distributors and other consumers are assured of uniform high quality when they specify certified wood fenestration products bearing the NWWDA Label.


The National Acceditation and Management Institute (NAMI) is an independent company which provides third party certification and inspecation services to the fenestration industry. The companies who participate in the NAMI pergrams are dedicated to produceing products compliant to industry standards. This program has been developed based on the parameters defined by the Department of Housing and Urban Development (HUD) and the American Nationa Standard Institute (ANSI).

Unlike the NWWDA that only covers wood products or AAMA that covers other selected products, NAMI certifies all types of fenestration products including wood, aluminum, vinyl, fiberglass and any combination thereof. Certification through NAMI is only valid when the product bears the NAMI Certification Label. The Certification Label will indicate the standard to which the product was tested. A code or name provides tracing of the manufacturing facility, the grade or performance level that was achieved, the series or model name of the product and other information pertinent to that product.


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