We have quadruple glazed windows with a center of glass insulation rating of nearly R10. The outer glass is laminated for strength, then there are two suspended Mylar films instead of glass to keep the weight down, and an inner regular glass layer. Each of the 6 interior surfaces has a low E-coating, so there are 6 glazing panes. Between each pane is Krypton gas; so one of our favorite jokes is that even Superman can’t handle these windows! 😉
The windows look fabulous and have features such as tilt and turn openings. They are made from extruded fiberglass so there is no PVC used – helps avoid some nasty chemicals used in PVC manufacturing process that companies like Dupont are not always very responsible about how they deal with chemical manufacturing by-products (see NY Times article on Dupont’s PTFE scandal, the film “Dark Waters” on the same topic).
They also provide excellent sound deadening. Living on Long Island, we have experienced several hurricanes (Category 2 Hurricane Irene, Superstorm Sandy) and various other storms. With the windows shut, we would see trees lent over but would not hear the wind howling. For this reason, we have had many neighbors spend stormy nights at our home instead of their own, it is easier to relax and sleep without the noise of the storm entering the house.
These windows are made a by company called Alpen. They are not cheap, we rather call them “the best windows your money can buy”. And we highly recommend them.
We recessed the windows 4″ into the wall (we had to build out the walls for this).
Recessed Single Unit 
Thickened walls to recess window 
Tilt & Turn Opening 
Regular Opening 
4 layers 
4 layers
