On Choosing Windows

Custom triple hung window

Choosing windows correctly could become a daunting task; there are many companies to choose from and even after you find the right company, there are lots of window types to consider. The following is meant to give homeowners an orientation of the relevant issues and aspects on this topic. I will discuss five ideas, in more detail:

1-    Choosing a reputable company.

2-    Understanding the relationship between the house’s character and the window’s “look”.

3-    Window types: casement, awning, double hung, sliding.

4-   Understanding the differences between applied mullions, simulated divided lights, and truly divided lights.

5-    Hurricane resistant windows.

The world of residential windows is divided into custom designed, semi-custom, and stock windows. Custom-designed windows are built to the architect’s specifications.  Every shape, mullion, and muntin can be designed to meet specific Owner requirements, window style, and operating mechanisms. Custom-designed windows are the most expensive, but they can also be the most beautiful, as well as the most resistant to wear and tear. They are typically made of wood, bronze, or steel. There are a number of companies in NY that produce custom designed windows; the most popular are: Zeluck and Reilly.

Custom curved windows

 Semi-custom and stock windows have standard mullions and muntins. You can choose standard sizes (stock windows) which typically vary in 4 inch increments or you can customize the window size to suit your opening. Examples of such companies are: Marvin, Andersen, and Pella. Some companies such as Weather Shield only make a composite window consisting of an aluminum or a vinyl clad wood frame facing the exterior and a wood frame facing the interior.

Semi-custom Marvin windows

Weather Shield windows

Comparing the different companies could be confusing, so a way to organize this is to use a spreadsheet. List all the important variables such as: durability of finishes, recommended maintenance schedule, pricing, warranty, impact category, size limitations, frame width, etc. and compare these with all the different manufacturers.

Window manufacturer's comparison sheet

Understanding the relationship between your house type and your window type is crucial when selecting windows.  In general, traditional houses require traditional windows such as double hung or casement, while modernist houses would look better with modernist window types such as awnings, fixed, or sliding.
  

Double hung

Casement

Awning

There are different “styles” within the “traditional” category, such as: Shingle Style, Colonial Revivals, or Greek Revivals. Each style requires a different window expression.  Greek Revival houses typically use double hung windows. Occasionally triple hung window are used, when opening unto a covered porch, so that the window looks like a French casement door but is more authentic to the Greek Revival style than an actual French door would be. Shingle Styles and Colonials may use a combination of double hung and casement windows, depending on their use, and location in the house windows. 

Triple hung windows opening to a porch

French casements opening to a porch

Different window types are favored in different regions of the world depending on climate and customary use. The use of in-swing casement windows and sliders seems to be generally favored in Europe.  Sometimes, houses with these window types also have exterior shutters.  Casement windows allow the user to open the entire window opening. By the same token in a rainy climate these windows offer less flexibility since, even the smallest opening exposes the entire height of the window to water penetration.

Double hung windows tend to be favored in the US. Their practical application is evident in that one can open the top and bottom sashes thereby allowing hotter air to escape from the window top and cooler air to penetrate through the bottom.  This arrangement also offers more protection from water infiltration, even when the window is ajar. Awning windows are useful in certain applications where one does not need a full sash opening but simply some ventilation.  Since they are hinged at the top and open outwards, they are particularly useful when the window is open, even if it is raining. Jalousie windows (a variation on the awning type) are favored in the Caribbean.

Jalousie windows and doors

 

Caribbean interior with jalousie windows

Independently of what type of window you end up with, if your house is traditional you will have mullions.  Mullions give scale to a window as seen from the exterior and to a room as seen from the interior. Large expanses of glass are mute regarding their size as they relate to a person and to the rest of the room. When a window sash is “broken up” into smaller panes you can relate to it better because each pane is roughly the size of your face. There are 3 ways to add mullions to a window. The least expensive and least successful way is to simply glue them to the glass face on the inside or the outside of the sash.  These are called applied muntins and they only give you the silhouette of what a traditional window looks like but, not the authentic look of the window. 

View through mullioned windows

 

View through open glass

The 2 ways to keep a traditional window “look” is by using truly divided lights or simulated divided lights. Truly divided lights do exactly what the term implies and divide each pane separately. This is how windows were built in the old days; an eminently practical solution since glass breakage could be easily repaired without having to change the entire sash. Modern windows are doubled glazed, for energy reasons. When truly divided lights are used on typical sized sashes with double glazing, the individual mullions get too large in proportion to the rest of the sash because, they hold more glass. The problem is solved by using simulated divided lights which keep the mullion size truer to the original sources; these are applied to both the inside and the outside of the glass faces.  This is not the same as using applied mullions because, there is a spacer bar in the space in between each glass pane which makes them look as if they are truly divided. Simulated divided lights are a standard feature of all custom and semi-custom window manufacturers.

Simulated divided lights

Applied muntins

Truly divided lights

 Regarding hurricane resistance, simulated divided lights tend to be more resistant than truly divided lights.  Building codes in coastal areas require hurricane resistant windows to meet a certain category of wind force or hurricane zone. Window manufacturers usually have pre-tested several typical window sizes so that they can ascertain how they perform during a hurricane.  Based on the results of these tests, the assemblies get a rating for certain hurricane zones.  The most restrictive zones, in the US, are in Florida.  It is for that reason that you may hear a manufacturer refer to a window as meeting the “Dade County, Florida, Code”.

Whether you are choosing custom, semi-custom, or stock windows, they are a considerable expense, so it is worthwhile investing a little time in researching your options before you purchase windows.  Keeping in mind the points made will enable you to make more informed choices.