Glossary of Terms

A-B        C-D        D-F        E-F        G-K        L-P        Q-S        T-W

The space in which the operating pad of the window requires clearance for fire regulations.

Elliptical Window
Curved top window which does not form a half circle since the curvature is less

Energy Rating
The Energy Rating (ER) value is calculated using a formula that balances a product’s U-value with its potential solar heat gain coefficient (SHGC) and its airtightness. The higher the number, the more energy efficient the product.

Fenestration (architecture), refers to the design, construction, or presence of windows and doors in a building.

Fixed Unit
A stationary window or door unit that does not open.

A thin strip of metal or synthetic material that diverts water away from a window or skylight.

The enclosing box of a window or door that surrounds a sash or sealed unit consisting of a head, sill and two jambs.

French Door
Hinged door available in one, two, three, or four-wide combinations with up to two panels operating.

Fusion Welded
The process in which PVC window corners are welded for strength and durability, ensuring a perfectly square and 100% weather–tight frame.