Why fixed glass
A picture window does not open, so there is no sash, no meeting rail and no weatherstrip to wear out. That gives the largest unbroken glass area for a given opening and usually the best air-leakage figure of any window type. It also costs less per square foot than an operable unit of the same size.
The obvious drawback is no fresh air. The usual fix is a fixed center flanked by operating units, most often casement windows on each side, or a double-hung on each side in a traditional house.
Adding a transom or shape
A rectangular or arched transom above a picture window adds height and daylight without changing the wall below. Transoms are fixed in most homes. On houses with arched openings over the entry or living room, the new unit must be measured as a custom shape, which adds lead time and cost.
Glass for big panes
- Sun: a large west-facing pane in a Knoxville summer is a heater. Choose a low SHGC coating for those walls, and compare samples so the tint does not dull the view.
- Safety glass: the 2018 IRC (R308.4) calls for tempered glass in a single pane over 9 sq ft when it sits less than 18 inches off the floor, reaches higher than 36 inches, and has a walkway within 36 inches of it. Many floor-level picture windows meet all four tests.
- Condensation: in January, the bottom edge of a large pane is the coldest spot in the room. Warm-edge spacers and a lower U-factor help.
- Noise: laminated or thicker glass reduces road noise if the view faces a busy road like Kingston Pike or Alcoa Highway.
Installation notes for large units
Picture windows over about six feet wide are heavy and usually need two or more installers and sometimes setting blocks under the glass. If the old unit has been leaking, the sill and rough framing below it often need repair, which is easier with a full-frame replacement. Ask whether the price includes interior trim and drywall return, which a larger frame can disturb.
Cost
Fixr's national range for a picture window is $300 to $1,600 installed. Oversized, tempered or custom-shaped units can run past that. These are national guide figures, not Knoxville quotes. The cost guide lists what else affects the total.
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