Double-hung window
A window with an upper and a lower sash that slide up and down. The plan shows the sash lines in the wall, with no swing.
This explains what a symbol represents on a drawing. Conventions vary between firms and standards, and a drawing's own legend takes precedence.
How to read it
In the Navy's Builder 3 & 2 course the two sashes slide vertically in grooves in the side jambs, and the window opens to at most half its area. The Army's print-reading manual uses the double-hung window as its example of a symbol that can't show movement: the sashes move perpendicular to the page, so the plan shows only the window in the wall. The Navy's Builder Basic course includes it among its window symbols.
Also searched as: sash window.
Look-alikes
A sliding window is drawn with its two sash lines offset, because its sash moves along the wall.
More blueprint symbols
Sources
- Builder 3 & 2, Volume 2, NAVEDTRA 14044, Naval Education and Training Command, U.S. Navy, ch. 4, double-hung windows
- Construction Print Reading in the Field, TM 5-704 / AFM 85-27, Departments of the Army and the Air Force, para. 2-2a
- Builder Basic, NAVEDTRA 14043A, Naval Education and Training Command, U.S. Navy, ch. 3, fig. 3-19
- Blue Print Reading: Interpreting Working Drawings, E. M. Wyatt, 1920, Bruce Publishing Company, Milwaukee (Internet Archive), Plan reading exercise
Last reviewed September 24, 2026 by Rory Hansen. How we research