A quick, plain-English glossary of the window and door terms you’ll run into when shopping for European windows and doors. Jump to any term below – and when you’re ready, explore our windows or call (435) 899-9862 for a free consultation.
Glass & energy terms
U-Factor
How well a window insulates – the rate heat passes through it. Lower is better. Important for both hot summers and cold nights.
SHGC (Solar Heat Gain Coefficient)
How much solar heat a window lets in, from 0 to 1. Lower is better in hot climates like Utah, Nevada, and Arizona. See best windows for hot climates.
Low-E (Low-Emissivity) Glass
An invisible coating that reflects heat while letting light through – cutting cooling and heating costs.
Double-Pane / Triple-Pane
Two or three layers of glass with insulating gas between them. More panes means better insulation and sound control.
Argon Gas
A harmless, invisible gas sealed between panes to slow heat transfer and boost efficiency.
Thermal Break
An insulating barrier inside a frame (especially aluminum) that stops heat from passing straight through the metal.
Window frame & material terms
uPVC
A rigid, low-maintenance plastic frame with excellent insulation and value. See uPVC windows and our frame material comparison.
Aluminum (Thermally Broken)
A strong frame with slim sightlines for large glass, insulated by a thermal break. See aluminum windows.
Wood-Clad
A wood interior paired with a weather-tough aluminum or uPVC exterior. See wood-clad windows.
Multi-Point Locking
Locks that engage at several points around the frame for a tighter seal and better security – standard on European windows.
Window style terms
Tilt-and-Turn
A European window that tilts in for ventilation or swings open like a door. See tilt-and-turn explained.
Casement
A window hinged on the side that swings outward, sealing tightly when closed.
Awning
A window hinged at the top that opens outward – great for ventilation even in light rain.
Double-Hung
A classic window with two sashes that slide up and down.
Picture Window
A large fixed window that doesn’t open, maximizing light and views.
Bay & Bow Windows
Windows that project outward from the wall to add space and light – bay uses angled panels, bow uses a gentle curve.
Egress Window
A window large enough to exit through in an emergency – required in bedrooms and basements by code.
Door terms
Lift-and-Slide Door
A large sliding door whose panel lifts off its seal to glide effortlessly, then drops for an airtight close. See sliding doors.
Pivot Door
A dramatic entry door that rotates on a pivot rather than side hinges. See modern entry doors.
French Doors
A pair of doors that swing open from the center for a wide, classic opening.
Bi-Fold Door
Panels that fold and stack to one side, opening an entire wall. See our door comparison guide.
Have a term we didn’t cover? Call (435) 899-9862 and our team will walk you through it.
