There are a limited amount of window products that are exempt from thermal performance testing (section NF1112.2 of the 2008 Oregon Residential Specialty Code). Among those exempt products are the following, if produced in low volume:

1. Windows;

2. Glazed doors;

3. Skylights; and

4. Solariums.

To qualify as a window product produced in low volume, a manufacturer cannot produce the above products in excess of the following maximums:

1. Windows, 750;
2. Glazed doors, 500;
3. Skylights, 1,000;
Skylights that meet construction standards and are produced in low volume
Skylights that do not meet construction standards and are produced in low volume
4. Complete solariums, 25.

Exempt fenestration products are also exempt from the thermal performance standards of the 2008 Oregon Residential Specialty Code. While these products aren't produced in low volume, they often must meet certain construction requirements. Exempt fenestration products can be either:

1. Complete solariums that have a minimum of 0.5 inch (12.7 mm) space between the panes; or
2. Skylights that have a frame type that is either aluminum with a thermal break, aluminum with vinyl, or wood, and a glazing type that is a minimum of either 0.5 inch airspace between double layered low-e or triple layered acrylic.

All window products that are produced in low volume and exempt fenestration products must have labeling that is:

• Imprinted, not handwritten;
  
• Faces the interior of the dwelling;
  
• Lists either the U-factor or U-factor class of the product; and
  
• Remains attached to the product until a building inspector inspects and verifies the labeling.

All window products that are produced in low volume and exempt fenestration products must comply with product-specific labeling requirements.