The framed window openings in a wall assembly are very much the same as door openings, with exception to the lower portion where windows have a sill. The windows found in older buildings may have many varieties of size and operation.

LISTEN PT 1...

Characteristics of WINDOWS on heritage buildings:

• Window parts include: frame, sash, glazing (glass), casing (wall trim) and sills.
  
• A window type is usually named in relation to its operation - how the window swings or is hung in the opening.
  
• The trim around a window and the profiles used to create frames and sash may match the general trim profiles in the building and relate to classical architectural orders.
  
• Exterior treatments at window openings will include materials for flashing and water shed. Caution: Some older buildings may have flashing made from lead.
  
• Panes of glass in windows are sometimes called 'lights'. Older windows may have blown glass panes, recognizable by their ripples and distortions.
• Glass panes were traditionally held in place by small, metal triangles called "glaziers points". The pane would be further seated and sealed with linseed oil putty or mastic. The process of installing glass in windows is called 'glazing'.
  
• The thin wood pieces that separate panes of glass are called 'muntin bars'. A thicker wood bar that divides groups of panes is called a 'mullion'.
  

Window TYPES:

LISTEN PT 2...

The diagram shown here identifies the operation and percentage of ventilation for various window types when they are fully open.

Other types / arrangements of windows include:

• Bay and bow windows
• Storm windows (applied to the exterior of existing windows in cold climates)
• Oriole windows (bay windows seated high on a wall)
• Ganged (many windows placed side by side)
• Picture windows (large, fixed windows, usually placed where a beautiful view is offered)
• Frosted glass (often used for privacy in bathrooms)