General Remarks

Windows may be merely openings in walls, generally that, or they may be projected from the general surface of the wall as hay windows, oriel windows, etc.

We have, however, in this course to deal only with the construction of the sashes and frames, and these should always, if possible, be flat, in order to avoid the expense of forms curved in plan, curved glass, etc.


The sizes of windows are regulated both by their external appearance and by the arrangements required for light and ventilation in the rooms.

Several rules are given by different writers for the sizes as regards external appearance. These need not here be entered upon. The undermentioned may be useful to regulate the size as regards internal arrangement.1

The area of light should = √ cubic contents of room. - Morris.

The breadth of window = 1/8 (width of room +height of room). - Chambers.

The height generally from 2 to 2 1/2 times the breadth.

There should be 1 foot superficial of window space to every 100 or 125 cubic feet of contents of the room in dwelling-houses, or 1 foot superficial to 50 or 55 cubic feet in hospitals. - Galton.

The window sill should generally be about 2 feet 6 inches from the floor inside.

Windows should (as nearly as the construction will admit) reach to the ceiling, for the sake of ventilation.

Sashes And Frames

Windows consist of two parts - (1) The sash or sashes (including the bars) which hold the glass; (2) The frame carrying the sashes.

The sashes may be fixed, arranged in several different ways (see p. 265).

The frames may be solid or hollow. The latter (which are called " boxed or cased frames") are required to receive the counterweights when the sashes are hung over pulleys.

N.B. In the figures illustrating this section the parts are marked with the distinctive letters mentioned below: -

A . .


B . .


b . .


bl . .

Back lining of sash frame.

br . .

Bottom rail of sash.

c .


f ..


g . .


H . .

Head of sash frame.

h . .


ib . .

Inside head.

il . .

Inside lining of sash frame.

I . .


m r.

Meeting rails.

ol . .

Outside lining of sash frame.

0,9 .

Oak sill.

p . .


Pp. .

Pocket piece.

V .


pb. .

Parting bead.

ps . .

Pulley style.

psl. .

Parting slip.

s .


SS .

Stone sill.

SL .

Stone lintel, or window head. •

SF .

Solid frame.

sb . .

Sash bar.

sl . .

Sash line.

sk . .


t . .


tl . .

Top lining.

tr . .

Top rail of sash.

w .


WB .

"Wood brick.


"Water bar.

wp. .

"Wood plug.

WL .

"Wood lintel.


Window board.

x .


y . .


Y . .

Rough axed arch or concrete lintel.

1 From Notes on Practice of Building, printed at Chatham.