Articles » Excerpt from "Why... Buy Replacement Windows?"

Excerpt from "Why... Buy Replacement Windows?"

Tags: Windows & Doors, Energy-Efficient Windows, Skylights, Window Installation, Window Repair, Window Replacement

Chapter 1 – You live in a house – so you inherited windows. 
“Windows can be one of your home’s most attractive features.  Windows provide views, daylighting, ventilation and solar heating in the winter.” - - Department of Energy
When you bought or built your home did you actually count the number of windows in your house or calculate how many square feet of glass your house is composed of?  
Your windows may be double hung, casement, sliders, fixed lite (and there’s more).  The glass may be single pane, or multi-paned.  They may have frames made of wood, metal, vinyl, fiberglass or composite materials.  They may have obsolete hardware and outdated balances (they’re the things that help the window go up and down).
If you’re like the majority of homeowners, you liked the general design of your home, the layout of the rooms and its proximity to schools, places of worship and shopping.  Much of the other “stuff”, including the windows, was something you took for granted.
I have spent most of my adult life in and around the construction industry, as well as home remodeling and home improvement.  Despite this, I am - like you - a homeowner.  Much of what I will write about in this book is biased because of that fact.  I have sat through hundreds of presentations for new products and new manufacturing methods.  I have been privileged to know and work with many of the pioneers who created, manufactured and marketed windows of all kinds. However, this book is being written to and for homeowners not too much unlike myself.
The concept of glass in the walls in your home is a given.  The fact that glass has existed as a method for transmitting light and visage for hundreds of years has been of little importance to most homeowners.  Yet in the last 30 years the advancements in the production of glass as well as the many options available have been a great benefit to our society in general and homeowners in particular.
As you read this book, remember, that our goal is to aid you when the time comes to replace your windows, and also to give you a better understanding of the kind of replacement windows and glass packages which will have the most beneficial effect on your lifestyle and your budget.  In chapters 5 and 6 we will examine in detail the best methods to install replacement windows and how to select a replacement window contractor.
First, let us examine some history to better understand the original intent of a window vs. the needs of homeowners today.  Most wordsmiths agree that the word window is Scandinavian in its origin and is a conjunction of several words which are interpreted as “the eye of the wind” or “wind’s eye”. 
Unquestionably, those ancient Norsemen were motivated by the fact that the word “home”, literally translated, was a place where people lived.  They cooked in and heated the interior of their homes by whatever methods were available at the time.  Most of these were enclosures that provided no ventilation or opening for visage.  The absence “of” created the need “for.”
In all probability the original openings were installed high on the building and maybe even in the roof.  We speculate that this opening being high up in the enclosure offered a view of the sky (thus the part of the word meaning eye).  Probably because Norwegian winters consist of low temperature and howling winds, the name “wind’s eye” seemed appropriate.  Later, our language in typical fashion created the English word: window.
So now, how many windows do you have in your home?  And how many square feet of glass do you have in your entire house?  In truth, we homeowners love the idea of being able to look out and allow daylight in, giving light to the interior of our homes without throwing a light switch. 
We also like to decorate around our windows, inside and out.  We have specialists who design “blinds” in shaded colors to fit our interior design.  We spend many dollars on drapes which can be drawn to give us privacy at night and add décor to our interiors.  We place shutters to the sides of our windows with no intention of ever closing them (which was the original intent – to shut out wind and rain).  And we certainly don’t wish to complicate our lives by counting the square feet of glass.
We Americans (Canadians also) love our windows and as ceilings got higher and houses in general got more expansive, we took for granted that more and more windows were natural. “So what?” 
Here is the challenge we face with our homes today.  Most modern houses were built with 1 opening per 100 square feet of exterior wall space.  If the average window in a home is 6 foot high by 3 foot wide, that equals 18 square feet within the 100 square feet.  While discounting the area for the frames, but allowing for the glass, this might mean that as high as 15% of the exterior wall area of a house is glass, which represents the most vulnerable part of the walls and the insulation system of your home.
The Department of Energy ( has produced numerous studies relating to this vulnerability.  Think of it this way: your home loses or gains heat through its windows.  The walls, floors and ceilings of a home may be well insulated and meet the best “R Factor” standards.  Despite this, the glass in a window can radiate the heat manufactured inside the home to the outside in the winter. In the summer or in deep southern or western climates, the issue changes and here the outside heat tends to penetrate glass, thus reducing the effectiveness of an air conditioning system.  In these climates, this factor is referred to as a solar heat gain coefficient (SHGC).  It refers to the fraction of solar radiation passing through the window as heat compared to the amount of solar radiation striking the window.  This latter rating, together with the (R) and the (U) factors can be specified when someone is replacing their windows.  Many older homes have windows with single panes or double panes without special heat-saving coatings.  This condition, coupled with loose or aging frames around the window will contribute to excessive heat loss or gain.
The (R) Factor – the resistance to heat flow or the degree to which a material resists heat transfer.  The higher the R-Value, the better the insulating performance.
The (U) Factor – the measurement of how much heat is transferred through a window.  A lower U Factor represents better insulation and less heat flow.

When and if you decide to have your windows replaced, this information will be beneficial.  In chapter 6, we will describe how to include this in the specifications as a part of your contract.
The Department of Energy estimates that 20+% of heat loss or gain may be due to radiation which comes through poorly or non-insulated glass.  It is not uncommon for apparently well-built homes to have windows that measure a high (U) Factor (which is undesirable).  In addition to the heat loss or gain being radiated through the glass, additional loss or gain may come from the loose or aging frames around the window.  To reinforce this point, here is a direct quote from a Department of Energy publication:
“Windows can be one of your home’s most attractive features.  Windows provide views, daylighting, ventilation and solar heating in the winter.  Unfortunately, they can also account for 10% to 25% of your heating bill.  During the summer, sunny windows make your air conditioner work two to three times harder.  If you live in the Sun Belt, look into new solar control spectrally selective windows, which can cut the cooling load by more than half.”  (“Energy Savers: Tips on Saving Energy and Money at the Home”, a Department of Energy publication.
The Department of Energy publications are replete with advice on how to reduce the cost of energy in your home, a major factor of which relates to inefficient windows.  If you check your windows now and find the glass is single pane, you probably would have been wise to replace them sometime ago.  You may have already paid for replacement windows if you have lived in this house for seven to ten years. 
If you are reading this book on a day when the temperature is cold outside and your heating system is working at making you warm and toasty try this experiment: While inside your house, simply place the palm of your hand on an outside wall, not too far from your window.   Then, place it on the glass in the nearby window.   The difference in temperature begs the question - why is there such a radical difference?
Next, with some caution (be sure your drapes are out of the way), while standing in front of the same window, light a match or lighter and hold it approximately 1 inch away from the pane of glass.  You will notice that the flame is attracted to the glass and will constantly bend in that direction.  This experiment shows how the heat being manufactured in this small light is being radiated through the glass.  Now think of a hundred or even a thousand of these little flames being held in front of this same window and you may perceive the concept of heat loss.
There are other tell-tale signs which indicate whether the efficiency of your windows is currently in good standing.  Take the following steps on your own to see if you’re a candidate for a complete window inspection. 
Start by opening each window.  If it is a conventional double-hung (the lower sash lifts up and the upper sash can be pulled down) check how easily this works and remember as you do, in the event of an emergency such as a fire you might be forced to exit your house by this route. 
Some of your windows may, when unlocked, slide side-to-side (they’re called sliders).  And some of your windows may crank in and out with a handle at the lower part of the window (most of these are casements).  These actions alone will make you aware of conditions you may never have thought of. 
Occasionally, your windows may be difficult to move because the connections between your sash (the part that holds the glass) and the frame (the part that surrounds the window) have been over-painted, which will cause them to stick when you attempt to open them.
After reading this chapter, don’t be upset with the builder, the manufacturer of the windows, or the person who installed them if you live in a relatively new home with windows in poor condition.  Chances are that when you previewed this house before you bought it, you gave extra attention to the kitchen and the bathroom.  Realtors tell us these are the two main attractions (rooms) for prospective buyers.  So, don’t berate yourself either, because you did not check out the windows when you purchased your home (this is normal).  Do remember, you live in a houseso you inherited windows – so it is wise to take care of that which you have inherited from here on out.


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