Window basics

I love windows. Architects have called them the erogenous zone of walls. Floral Stained Glass

They are critically important design elements and an important part of construction.  While they enable one to look out they also allow the passage of light, air and noise into and out of buildings.  They must be carefully considered where they are located for views, for lighting, for human comfort and thermal comfort inside as well as aesthetics.  In certain situations they must be adequately sized for emergency escape as well as firefighter’s entrance into the space.

Window Anatomy

Before we can talk about types of windows, we need to understand the anatomy of a window:  Generally speaking a window fills a hole in the wall with different materials and is fixed or operable.  The part that is attached to the wall is called the window frame, the part that moves is called the window sash.  The way that the window sash moves generally determines the type of window.  The primary types of windows consist of: casements, double hung, sliding, and jalousie.  Other important parts of windows that should be understood are the meeting rail which is where two sashes come together, Muntins which are the little to divider bars that make the window sash appear to be in several pieces, the sill which is the bottom, the head which is the top, and sides which are called the jamb.


The casement window means that the sash swings on hinges usually from the side but sometimes from the top and occasionally from the bottom.  The type of casement that is hinged at the top is called an awning window- they are frequently found in basements and schools.  The type of window that is hinged on the side is very common and is often operated with a small crank at the window sill or sometimes the small piece of hardware that you push.  The type of window that is hinged at the bottom is called the hopper window this is also used at homes and schools and industrial buildings.  Sliding windows are frequently used in homes, commercial and residential apartment.

The material for most windows frames are made of the following: wood, wood clad with metal or aluminum, fiberglass, or other composite materials.  The glazing which is in the sash, mostly is made of glass- the portion that you look through.  But sometimes it is not glass- it can be made of Plexiglas or other safety glass for safety reasons or other types of semi-transparent materials for privacy or even materials that are fully opaque and decorative.  Sometime this sashes are filled with screens or other filters to allow air or light to pass through.  Leaded and stained glass are also beautiful components in many types who windows.

New window glass is typically insulated- which means that there are actually several layers of glass and a space in between the layers of glass filled with gas that has good insulating properties such as argon.  The actual glass layers often have different coatings on them to help minimize passage of harmful UV rays and heating rays from the sun.

Several well larger manufacturers of windows include Marvin, Anderson, Zelluck, Pella, Hurd, Jeld Wen, and Kolbe and Kolbe.  You’ll find that prices vary dramatically especially for unusual shapes/sizes and custom size units.  Because of the potential for poor thermal performance and safety, it is a bad idea to scrimp on good quality windows.