Tempering Requirements
Tempered glass is glass that has been heat strengthened to the point that, if
broken, it will shatter into hundreds of blunt pieces that will not seriously injure a
person or animal. Tempered glass is required in:
  • All doors
  • Any glass in a window that is within 2 feet of a door
  • Any window with over 9 square feet of glass IF it is within 18" of the floor
  • Any window glass within 60" of the floor, that is over a bathtub or in a
  • Any window glass within 60" of a stair step or landing
Additionally, if you live in a fire zone (which includes all of Laguna Beach, then
one of two panes of ALL new windows in Laguna Beach (fire dept regulation)

Low-Emittance (Low-E) is a term used for a surface that radiates, or emits, low
levels of radiant energy. Emittance refers to the ability of a materials surface to
emit radiant energy.  Reflectivity is inversely related to emissivity and when
added together their total should equal 1. A low-e material such as aluminum foil
has an emissivity value of 0.03 and a reflectance value of 0.97, meaning it
reflects 97% of radiant energy and emits only 3%. Low-E building materials include
window glass manufactured with metal-oxide coatings as well as housewrap
materials, reflective insulation's and other forms of radiant barriers.

To make Low-E glass, specially designed coatings, often based on metallic
oxides, are applied to one or more surfaces of insulated glass. These coatings
reflect radiant infrared energy, thus tending to keep radiant heat on the same
side of the glass from which it originated. Radiant heat originating from indoors
is reflected back inside, thus keeping heat inside in the winter, and infrared
radiation from the sun is reflected away, keeping it cooler inside in the summer.

The most important things in installing windows are
a) rough framing - proper size header; king stud and trimmer
b) proper waterproofing the rough opening - cut 45 degree diagonal flaps in the
Tyvex building wrap; fold in bottom Tyvex flap; install either rigid sill plate or we
recommend bithuthane on the bottom sill; fold in Tyvex sides, tape horizontal
seam between Tyvex & Bithuthane;
c) proper squaring - the most accurate way to double check this after (rough)
installation is to measure the two diagonals - they ought to be within 1/8 inch
d) proper flashing post window installation - install drip cap; tape sides of Tyvex
to window; tape top on window to framing; finally fold down top Tyvex flap on top
of window (over tape) and tape the 45 degree diagonals on the upper corners
e) proper sealing and insulation - from the interior, apply a bead of low
expansion foam on the backside of the exterior casing

In a standard installation, windows are installed flush with the outside wall.  
When the cladding is siding or stucco, this is appropriate, as it leaves as deep a
well as the wall width will allow on the interior.  However, when the cladding is
stone, it is often desirable to have the "recess" effect both on the interior AND
on the exterior.  In this case, after the windows are installed, a second wall is
built on the exterior, on which eventually is applied the stone.  The inset
windows achieve the robust look of a full block stone vs a relatively thinner

Sample manufacturer window installation instructions