Window Restoration Glossary

Awning windows

An outward swinging window unit opening from the bottom and hinged at the top. Benefits of this window style include […]

Bow sash window

The bow sash (or bow-faced sash) is a unique and particularly attractive form of sash window. Existing in a few […]

Conservation Glazing

Conservation Glazing refers to high-performance window upgrades—such as slimline double glazing or vacuum insulated glazing (VIG)—specifically designed for use in […]

Casement window

Casement windows are one of the primary designs seen through the last three or more centuries of window history. A […]

Draught-Proofing

Draught-proofing (sash windows) involves sealing the moving sash gaps to stop cold air from entering while enhancing heat retention and […]

Double glazing

Double glazing is a window construction method which employs two glass panes that remain separated by a sealed air or […]

Dormer window

Dormer windows are instantly recognisable features of much historic European architecture and describe a window set into a sloping roof. […]

Georgian sash

Georgian sash windows are characterised by their elegant, symmetrical design and multi-pane glazing—most iconically in a six-over-six configuration (six panes […]

Low-E glass

Low-E (low-emissivity) glass contains a thin metal coating which allows sunlight to enter but bounces heat back into the room. […]

Sash cords

Sash cords are the braided cotton or synthetic ropes traditionally used in counterbalanced sash windows to connect the moving sash […]

U-value

U-value measures how effectively a window resists heat transfer—the lower the U-value, the better the insulation. Expressed in W/m²K (watts […]

Vacuum Insulated Glazing (VIG)

Vacuum Insulated Glazing (VIG) is an advanced, ultra-thin double-glazing solution ideal for historic and period properties. The VIG system employs […]