Single & Double Hung

Single Hung
Alcor Single hung uPVC Windows

A single hung window consists of two sashes, one on the top that does not move and another  on the bottom that does move vertically. Contrast single-hung windows with fixed windows (consisting of one sash that does not move) or double-hung windows (consisting of two sashes, both of which move up and down).

Double Hung

Alcor Double Hung uPVC Windows

In double-hung units, both sashes slide vertically. Ventilation area can vary from a small crack to an opening of one-half the total glass area. Screens can be placed on the exterior or interior of the window unit.
Note: Double Hung windows does not come in standard sizes.