We dedicated this section to:

  • Making sure that you will not overlook the importance of the window frame.
  • Explaining why vinyl windows continue to be the most popular choice.
  • Helping you spot a quality vinyl window frame.

Why you shouldn’t overlook the importance of the window frame.

Most homeowners focus on thermal properties of the window glass when shopping for replacement or new construction windows. This is a good start in the search of the best window for your home. An average window comprises roughly 80% of glass and the window’s thermal performance depends mainly on the quality of the glass. Therefore, window glass will probably have the greatest impact on keeping the energy costs low.

But what about remaining 20% of the window? Like with many other products, we buy for our homes windows consist of many important parts. The quality of those other parts will contribute to the overall quality of the windows you buy. This will translate into the following benefits for you as a homeowner:

  • Increased comfort in your home year-round.
  • Increased energy savings both during winter and summer helps with energy bills.
  • Trouble-free operation prevents unnecessary frustration and saves you time on service calls so you can go on with your life.
  • Longevity of the windows. If you buy quality windows those will probably be the only windows you’ll ever need.
  • Enhanced beauty of your home’s exterior as well as the interior.

When you shop for a car, you consider many different aspects such as the engine performance, the look of the car, comfort and many other things. If we were to compare an insulated glass unit in a window to an engine in a car, we could easily compare a window frame to the car’s chassis and body. We almost never make a decision to buy a car based solely on the engine performance. We look at the quality of the other components too. We also want our car to be reliable and to look well. We want to make certain that we get good value for the money.

So whether shopping for replacement or new construction windows, we advise that homeowners in Connecticut keep in mind the importance of structural integrity, thermal properties, and overall design of the window frame.

Vinyl windows are the number ONE choice in Connecticut and the U.S.

When shopping for replacement or new construction windows, your choice comes down to: wood, aluminum, fiberglass, composite and vinyl. While fiberglass and composite materials slowly gain more popularity, Vinyl windows remain the most popular choice for homeowners in Connecticut and nationwide. Here’s why:

Excellent Thermal Properties

In respect to energy efficiency, vinyl windows outperform competitive products due to non-conductive nature of the vinyl material. Unlike aluminum, vinyl does not conduct cold. Moreover, it provides higher insulating U-factor than aluminum. Also, vinyl windows resist condensation better than aluminum, which is notorious for condensation and even frost inside home in very cold weather.

OKNA EnviroStar Double-Hung DeLuxe

OKNA Bay Window DeLuxe

High quality vinyl window frames and sashes are fusion welded for protection against air and water infiltration. Plus, vinyl frames are constructed of various sized multi-airspaces, or chambers. Airspaces with dead air trapped inside are an excellent barrier to heat transfer. However, when those air chambers are filled with quality insulation, the energy efficiency of the frame, hence the entire vinyl window, is further increased.

High Durability and Low Maintenance

Vinyl does not rot, rust, corrode, blister, or flake and is impervious to termites and other insects. Unlike aluminum, it resists attacks by fungus and mildew. Vinyl frames do not need painting, staining, scraping, and sanding. Also, if the frame ever gets scratched, it will not require any touch up. With most other materials, the color may change or fade overtime. That is not the case with high quality vinyl windows. The window manufacturers who use only the best ingredients in the production process, produce quality windows whose pure white color will last for many years. Quality vinyl windows are so durable that the vast majority of them installed over the past 30 years are still in use today.

Health and Safety

Health and safety of your family are the most important thing to you. Think about it when you purchase new windows. Government agencies as the U.S Food and Drug Administration, the U.S. Environmental Protection Agency, National Sanitation Foundation and Consumer Product Safety Commission set forth certain health and safety requirements. Quality vinyl ingredients can be formulated into vinyl frames that meet those requirements. Consider these facts:


  • Quality vinyl windows resist growth of mold and fungus – especially important if you have children.
  • Quality vinyl windows resist moisture, corrosion, and household chemicals.
  • Quality vinyl windows do not support combustion and require high temperatures for ignition. Wood burns readily and some finishes increase its flammability.
  • Quality vinyl windows have certain security features that make it more difficult for the potential intruder to break into the house.
  • Design flexibility of vinyl windows allows for producing windows that meet or exceed building codes in regards to sufficient opening to escape the building in case of fire. Properly designed, measured and installed vinyl windows can serve as emergency escape routes.
  • Often paint, dirt or weathering can seal a window shut. Delays in escaping from a fire cost lives and increase injuries. Make sure your windows open easily from the inside and are not blocked. Quality vinyl windows are very easy to open. And since they do not need to be painted, sealing the window shut is eliminated.

Environmentally friendly

Vinyl windows are eco-friendly because the main ingredient used to produce vinyl resin is common salt. Common salt is sustainable and an abundant natural resource. Also, there is no need to use wood to make vinyl windows, which reduces impact on forests depletion. Vinyl can be easily recycled into other useful products further reducing the environmental impact of waste. And because vinyl windows are exceptionally energy efficient and weather-tight they reduce fuel consumption needed to heat and cool homes.

Design Flexibility Equals Better Value for the Money

Vinyl frames are easily manufactured in custom sizes and configurations. Unlike stock windows that you can buy off the rack at home improvement stores, custom vinyl windows can be manufactured to the nearest 1/8” to perfectly fit into your specific window opening. And generally will not require any alterations to your walls. Also, vinyl can be easily bent into shapes, which makes the manufacturing process simpler and less costly. So if you ever need special shape windows consider vinyl because more than likely you will get beautiful windows for less money than aluminum, wood or fiberglass.

What to look for in a vinyl window frame?

Like with other products, not all vinyl windows are the same. Use this guide to spot quality vinyl windows that will be aesthetically pleasing, lower your energy bills, and boast long service life.

Quality of Raw Materials

When you prepare a meal, the quality of ingredients you use will determine the smell, look and taste of the food. The same rule applies to vinyl windows. Vinyl windows are made using polyvinyl chloride (PVC) or un-plasticized (uPVC). PVC and uPVC are made by formulating several ingredients. Those ingredients are available for the manufacturers in different levels of quality and in different price levels. Some companies choose to compete on price and some on quality. One problem with low quality vinyl windows is that they are not really white, but they are a polar blue shade of white. It’s difficult to spot the difference at first but if you compare the two windows next to each other, then the difference is dramatic. High quality vinyl window frames are made of pure vinyl virgin resin that has never been used and is a pure white color. Lower quality windows are made of “pellets”, which is a recycled material and has polar blue shade.
The ingredients that make vinyl stay pure white for years are:

  • Titanium dioxide (TiO2) – pure white chemical also used by the paint industry to make pure white paints.
  • Weathering pigments
  • UV stabilizers

One of our suppliers, Alside, custom-produces each window from pure vinyl resin in combination with the best stabilizers, impact modifiers and highest amounts of titanium dioxide for consistent color and strength. Our other supplier, OKNA, custom-manufactures all the vinyl windows using un-plasticized vinyl material (uPVC).

Read the AAMA Labels – American Architectural Manufacturers Association

You can find structural integrity rating, known as DP-Rating, on AAMA labels. The higher the DP rating, the stronger the window is. AAMA tests windows for structural integrity and parts of the certification process are:

  • Missile impact test
  • Testing before and after weathering
  • Pressure test
  • Drop impact test

Frame Assembly

Vinyl window frames can be either mechanically fastened (screws) or fusion (heat) welded. Mechanically fastened windows will perform well if installed correctly. However, fusion-welded windows outperform mechanical windows when it comes to air infiltration, energy efficiency, and structural integrity. Simply the welding process creates one weather-tight piece of vinyl frame.

Multi-Chamber and Insulated Frame

The frame is constructed of differently sized air chambers. Chambers are supposed to hold trapped air. Trapped air is proven to be a great insulator. Insulated frames are also available. Insulation further increases energy efficiency of the frame. Another benefit of multi-chamber design is strength and rigidity of the frame. In short, the more chambers the window has the more energy efficient and sturdy the frame is.

European Style Windows and Patio Door Frames

Other Important Features of The Best Vinyl Windows

  • Metal or Composite Reinforcements are crucial for window strength at the meeting rails. Make sure to check the cross-section of the window for a metal or composite structural reinforcement.
  • Interlock at sash meeting rails creates a tight seal against air infiltration.
  • Weather-stripping is another feature that protects from weather infiltration so make sure your window has plenty.
  • The sill dam that is mortised into the window jamb adding strength and lowering the possibility of leaks that may occur at corner seals.