In selecting windows to frame any view, it is important to avoid those having obstructions which interfere with the view. The windows should be placed at carefully determined heights so that the sills and intermediate divisions do not obstruct the line of sight, either that of tall or short adults.
The following recommendations for placement of windows serve as a check list of good practices.
To minimise obstructions in the line of sight, use fixed glass except in
those areas where ventilation must be provided. Screens are not needed
on fixed glass and, therefore, eliminate another interference from a
standpoint of view. Windows having slight divisions are acceptable. A
horizontal division more than 1OOmm thick is not desirable when the
division falls in the line of sight. Vertical divisions are not as objectionable
as horizontal ones.
Determine sill heights on the basis of room use and furniture
arrangement.
Windows 
