Replacement Window GuideSystems index
Window Types: Double-Hung, Casement, Sliding, and Bay
Compare replacement window families: double-hung, casement, sliding, and bay and bow windows, with how each operates, seals, and fits your openings.
Awning Windows: Top-Hinged Ventilation and a Refrigerator-Door Seal
Awning windows hinge at the top and crank outward from the bottom, forming a small canopy that lets them stay open in the rain, and their single-sash compression design gives them one of the tightest seals of any operating window.
System typeBay and Bow Windows: Structure, Space, and Cost
Bay and bow windows both project outward from an exterior wall, but a bay uses three windows set at angles while a bow uses four or more equal-size windows to form a gentle curve. The difference changes the shape, the interior space, and the amount of light.
System typeCasement Windows: Seals, Full Ventilation, and Hardware
Casement windows are hinged on one side and crank open outward like a door, which gives full-sash ventilation and, when the crank pulls the sash tight against the frame, one of the most airtight seals of any operating window.
System typeDouble-Hung Windows: Operation, Ventilation, and Cleaning
Double-hung windows have two operating sashes that move up and down, letting you ventilate from the top, the bottom, or both, and most tilt inward for cleaning. This guide covers how they work and what their energy label numbers mean.
System typeGarden Windows: A Projecting Box With Side Vents and a Tempered Top
A garden window projects outward from the wall to form a small glass box with shelves for plants, operable side windows for airflow, and a sloped tempered-glass top.
System typePicture Windows: Fixed Glass, Maximum Efficiency, Uninterrupted View
A picture window does not open, and that single fact makes it the most energy-efficient window type, because a fixed sash gives air almost no path to leak in or out.
System typeSingle-Hung Windows: One Operating Sash, Lower Cost, Fewer Leaks
A single-hung window opens only from the bottom while the top sash stays fixed, which lowers its price, reduces maintenance, and gives air fewer places to leak than a double-hung.
System typeSliding Windows: Wide Openings and Maintenance
Sliding windows, also called gliding windows, move horizontally along a track instead of swinging or lifting. Their horizontal shape suits wide openings, and with fewer moving parts they are simple to maintain.