An Architect’s Guide on How to Choose Windows for New Construction
If you’re looking for an architect’s guide to windows, you’ve come to the right place! From Sash Windows, Double Hung Windows, to Hopper Windows, you will have a better understanding of the different types of windows and materials and will be able to choose the best windows for your newly constructed home!
Window Types and Technologies with its Operating Types
European Tilt & Turn Window
Tilt and turn windows are unique in the sense they open on two different axis. The window can be tilted open, usually from the top, allowing for excellent ventilation and airflow, even during rainfall. The window tilts open in this manner to maximize the efficiency of air circulation, bringing cool air towards the ceiling and pushing the warm air down, creating the circular air movement desired for clean fresh air flow. The window can also be opened fully on a side axis, which is most often used for cleaning the window’s exterior or for the ability to escape a room via the window in the case of an emergency. Tilt and turn style windows account for the majority of windows purchased in many European countries, however, this technology has yet to be adopted on a wide scale in North America.
Fixed or Picture Window
A Fixed Window is a non-operable unit, meaning it consists of a stationary window frame that can not be opened. A Picture Window is also a non-operable window however, in comparison, large picture windows usually have a lower profile frame, maximizing the glass surface to create clear, unobstructed views. Fixed Windows are often aligned with operable windows of the same style and size to create expansive and open views across a wide space and allow for ample natural light to enter the room. Non-operable windows can also be manufactured in larger sizes as the frame does not need to support heavy-duty hinge hardware that would permit thicker glass units to rotate and open.
- Single hung windowsA Single Hung Sash Window refers to a window unit in which there are two sashes, one is operable and the other is non-operable. The most common example of this type of unit is one in which the bottom half of the window can be unlatched and slid upward, in alignment with the upper non-operable sash to allow for airflow into the room.
- Double hung windowsA Double Hung Window uses the same window design as a Single Hung Window, however, both the two sash units are operable. The most common example is a window that can be unlatched and the lower sash slid upward and the upper sash slid downward.
- Single Sliding WindowsSingle Slide Window units have two sash units, side-by-side, which open horizontally and consist of one operable sash and one non-operable sash.
- Double Sliding WindowDouble Slide Window units have two sash units, side-by-side, which open horizontally and consist of two operable sashes.
Casement Windows are attached to their frame via one or more hinges and open using a crank mechanism. They can be opened to varying angles based on how many times the crank is turned.
Awning Windows are Casement Windows that are hinged at the top and swing open outward via the turning of a crank mechanism.
A Hopper Window refers to a small horizontal window, usually installed in either the basement or in a bathroom, that opens from the top. The bottom of the window swings outward while the top of the window swings inward when opened.
Window Materials and Performance
UPVC is affordable, extremely durable, easy to care for, not affected by moisture, has a low conductivity, and is very flexible under high heat, permitting for unique shaping and design opportunities.
Aluminum is lightweight, offers a high degree of stability, can be offered in a range of different surface treatments, and can provide narrow frames for expansive views.
Wood frames are a frame material that offers natural beauty and a cozy feel. Wood is a less modern window material however it has low thermal conductivity and high strength. The concern with full wooden frames is longevity with the possibility of rot and deterioration over time.
Hybrid frames such as UPVC – Aluminum or Wood – Aluminum are becoming more common in parts of the world as they combine the strengths of different materials to provide a combination of performance and esthetic pleasure. An example would be an Aluminum – Wood window frame with aluminum on the exterior of the home, providing excellent resistance to weather and water elements, with a beautiful wood frame on the interior that perfectly matches the flooring or furniture of the room in which it is contained. As with any of the above materials, the most important factor is the window systems design of the window unit itself. There are low-performing and high-performing windows of the 4 materials listed above for which the number of glass panes, the thickness of the glass, the composition of the frame extrusion, air seal tightness, and, other factors will ultimately determine the quality of the unit itself.
Aesthetics – Components of a Beautiful Window
Color / Texture
The world’s top window manufacturers are capable of creating vast scales of color options based on the material composition of the frame. For example, UPVC can be wrapped in a “foil” that can almost literally be any color or grain texture desired. There are obvious limitations and manufacturers have their standard series of options, however, the technology permits near limitless variety. Aluminum can also be powder coated via an electrostatic charge process that adheres to the surface providing a wide range of color options, based on the powder selected, and this process even improves the durability of the aluminum frame creating an external barrier between the elements and the aluminum surface.
For wood enthusiasts, there is likely nothing more appealing than a wood frame window. Whether the frame is made of spruce, oak, ash, walnut, larch, or other varieties, you can match the color to the interior décor elements for a design that stands out. The wood can be stained to a variety of different hues to hit exactly the color note desired. For some, who appreciate the texture of wood but would prefer something other than the natural grain pattern to show through, wood frames can be painted in many colors, the most popular being white, cream, or black.
Another aspect rarely considered during the window selection process is the style of glass within the unit. Glass can be manufactured in a variety of different hues, and opacities and can have varying functional performance such as anti-glare to prevent interior glare from happening, and you can even get an insulated glass unit with improved thermal insulation, shatterproof lamination, etc. Not all manufacturers offer these different features and they usually come at an added cost, however, the glass itself can be curated to fit your exact needs via certain suppliers.
Thermal Transmittance (U-value):
The U-value, also known as thermal transmittance, is the rate of transfer of heat through a structure divided by the difference in temperature across that structure, often expressed in the units of measurement W/m2K. In simplistic terms, the lower the U-value on a window unit, the better that window is at restricting heat exchange between the exterior and interior of your home, reducing the energy required to both heat and cool your residence. When comparing window options, look for the lowest U-value possible!
Visual Light Transmittance (VLT):
VLT is a percentage-based expression that provides a measure of how much visible light passes through the glass and into your home. Now for many, a high amount of light penetrating your home is a good thing as it brightens the space and makes it feel more open, however, that high transfer rate is usually accompanied by a high solar heat gain coefficient which can drastically reduce the energy efficiency and comfort of your home. Have you ever had to move away from a window during the summer because it was simply too hot? This was likely due to a high VLT rating. Unlike with U-values, there is not a simple “good or bad”, however, there are glass technologies such as special coatings that have less solar heat without overly restricting the amount of visible light into your home.
Conclusion: Benefits of Choosing the European Window for your Home
European Tilt & Turn Windows are not only beautiful windows, but they also offer the most advanced window technology and functionality available. If you require an operable window, it is highly likely a tilt and turns solution will provide the ventilation and emergency evacuation needs you require. Also, turn limiters can be added to these units to prevent the window from being opened past a certain radial degree, which is ideal for concerns with small children. With all of its benefits and features, European Tilt & Turn Windows are an excellent choice for your home!
Security – Four-sided interlocking operable window units are without a doubt one of the most secure additions to your home. Most residential window units have one or two latch points that secure an operable sash to the frame, whereas a four-sided interlocking unit has at least 8 latching points distributed throughout the entirety of the frame itself and are entirely self-contained and invisible when the unit is closed.
High Energy Efficiency – For the highest levels of energy efficiency for your home, you should consider triple-pane window panes with U-values below 1.0 W/m2K. The top market performers can achieve U-values in the 0.60 W/m2K range and these units are available for the supplier to the average consumer base.
Longevity – The duration of your window frames will vary on climate, weather conditions, regular maintenance, and material composition, however, you can create optimal conditions for your environment with sturdy, heavy, triple-pane windows with metal hardware such as is available on certain European triple-pane products.