Fenestration is defined as any opening, or arrangement of openings, in a building (normally filled with glazing) that admits daylight and any devices in the immediate proximity of the opening that affect light distribution (such as baffles, louvers, draperies, overhangs, light shelves, jambs, sills, and other light-diffusing materials). In other words, fenestrations are products that fill openings in a building envelope, such as windows, doors, skylights, curtain walls, etc., designed to permit the passage of air, light, vehicles, or people.
There are various fenestration systems like Glazing, Windows, Curtain Walls, Sloped Glazing and Exterior Doors. They can be explained as follows:
• Glazing: Glass which serves the purpose of allowing natural light into a building and weather shielding, has been in use for thousands of years now. This has led to glazing of majority of the new windows, curtain walls and skylights for commercial building construction for energy efficiency and comfort.
• Windows: The history of windows began prior to 1900, when windows in the U.S. were predominantly wood frame, with some custom metal windows (iron, bronze, steel) in institutional construction. Later, steel windows were introduced and then aluminum windows. By the 1990's, the latter accounted for approximately 65% of the commercial window market, while wood, vinyl and steel-framed windows comprise most of the remaining 35% of the market.
• Curtain Walls: A curtain wall is any exterior wall that is attached to the building structure and which does not carry the floor or roof loads of the building. This includes heavy wall types such as brick veneer and precast concrete panels.
• Sloped Glazing: Skylights have been used for over a century to provide interior daylighting. Most contemporary skylights now consist of insulating glazing captured in aluminum frames in many configurations (e.g. single slope, ridge, pyramid, barrel vault).
• Exterior Doors: These include entrance and exit doors, as well as industrial loading dock doors. It primarily addresses waterproofing and durability requirements.
National Fenestration Rating Council:
There also exists a Council - National Fenestration Rating Council (NFRC) that administers the only uniform, independent rating and labeling system for certifying the energy efficiency of fenestration products like windows, doors, skylights and attachments.