RSI for a single pane of glass is .18

-the optimum air space between panes of glass is 12 mm 

RSI=two panes .37, three panes .56 four panes .76

-two panes of glass separated by a reflective coating gives a RSI of 3 panes

-thermal breaks in metal frames reduce heat loss

-space between rough frame and inner frame is filled with backing rod

-polyethylene  wrap is sealed with a sealant

   -windows placed on the inside  (as opposed to the outside) of a thickened wall are more       energy efficient but harder to make water proof

SAMPLE INTERIOR WEATHER PROOFING 

-the space between the frame and the rough opening... USE BACKING ROD AND THEN CAULK... 

the interior wall vapor barriers  must be sealed against the moisture barrier for exterior wall 

use an acoustical sealant between poly and building paper 

- you can use a plywood liner sealed to vapor barrier and to  moisture barrier and to window frame and then drywall over plywood with a  plastic “j” bead against window frame

-Alternate to ploy barrier is  drywall wrapped...using a vapour barrier paint on the drywall



 fixed sash that would be your picture window, grilled and trapezoid
sliding sash that would be your slider and double hung
and swinging sash would include: hopper, awning, and casement
casement windows swing outward on hinges... on a blueprint the point indicates hinged side



Window sizes are given width first height second
 Almost universely they are given in feet and inches
for example a 3-0x4-6 window means 3 feet 0 inches wide by 4feet 6 inches high ...watch out for 3046 which means 3'0" by4'6" not 30"x46"


Window sizes are usually given wider than the rough opening
example a 3-0x 4-6 window would have a rough opening of 35 inches  wide by 53inches high

 Fire codes differ but there are minimum sizes that the window must open for bedrooms example: a minimum area of.35 square metres with no one dimension being under 350mm