fenestration

Fenestration is the building-products category covering windows, doors, skylights and glazed wall systems as a rated group. The cataloged reference is the NFRC Certified Fenestration Product Database, which organizes 741 manufacturers into 14 window, door and skylight product types and publishes per-variant energy ratings for each.

The category is defined by rating rather than by material. Every product type in the directory carries certified performance values, and the NFRC also issues label certificates for commercial projects through commercial.nfrc.org, which is the document a code official or project specifier asks for. Tags on the record include 'fenestration' and 'energy-code', which is how the category maps to compliance work.

• Ratings are per-variant, not per-brand. A manufacturer's line can span many configurations with different certified values, so a brand-level average hides the variant a buyer will actually install.

• Code compliance runs through the certificate. Commercial projects require NFRC label certificates from commercial.nfrc.org, so a dataset without certificate access cannot support compliance checks.

• Category coverage is countable. 741 manufacturers across 14 product types is a checkable denominator, and a source claiming full fenestration coverage should state its own.

1. Count the product types. The NFRC directory spans 14 window, door and skylight types, so verify a source covers the ones you sell or specify.

1. Check per-variant ratings. Certified values are published per variant, so confirm the source preserves variant-level rows rather than rolling them up.

1. Verify certificate availability. Commercial label certificates come via commercial.nfrc.org, which is the compliance artifact.

1. Compare against the u-factor. The u-factor glossary entry explains the rating itself, and a fenestration source should expose it as a field.

These entries cover the directory structure and the rating behind the label:

product directory is the directory pattern NFRC's Certified Products Directory follows, 741 manufacturers by 14 product types.

The rated window, door and skylight products behind this term sit in the catalog's building-products data page.