Windows are beautiful, and they’re functional, but they’re also a major source of energy loss in a home or commercial building. They are, after all, large holes in the walls. By definition, they have no insulation beyond what a double-glazed installation can provide. While some glass treatments can provide additional energy conservation through tints or polarisation, they’re still worse than walls when it comes to keeping your internal climate controlled.
Energy-efficient window coverings are an essential part of any modern building. They can lower climate control bills, whether you’re heating the building during a cold winter, or cooling it during a hot summer. To be clear, any window covering is going to provide some boost to the energy efficiency of your home, but only certain kinds of window coverings are truly energy efficient. If you want to get the most out of your window coverings, minimising your bills as much as you can, you need to pick one of these kinds of coverings.
There isn’t just a single type of energy-efficient window coverings – there are many different styles for both indoors and outdoors. This guide will give you more information on each option, as well as show you some examples, to help you make an informed decision.
Let’s get started!
Operable or Inoperable Coverings
The first decision you have to make is whether you want an operable or an inoperable window covering.
Operable window coverings are window coverings you can adjust and move when you want to change their position. Blinds, curtains, shutters; all of these are operable coverings. If it’s a sunny day, you can pull them closed. If it’s a dim day, or if you want more natural light, or if you simply want to see the view outside your windows, you can draw them back.
Studies have shown that, in as many as 75% of cases, operable window coverings are not typically operated. If you’re the kind of person to leave the blinds where they are, keep the curtains drawn back, or never pull the shutters closed, you won’t gain many benefits from operable window coverings like these.
Operable window coverings are often more beautiful than inoperable coverings, and they do always provide the option of adjusting them, even if you don’t use them.
Additionally, some operable window coverings can be made automatic, adjusting with the press of a button or on a fixed schedule at certain times of the day. This is generally more expensive but is a much easier and more carefree way to make use of operable window coverings.
Inoperable window coverings, meanwhile, simply attach to the glass of the window and cannot be removed easily. Window films, for example, apply to the glass and put a layer of UV protection, tint, or polarisation to the glass to minimise energy transfer. They provide a permanent solution to energy loss through windows, but they can’t be rolled back out of the way if you want to see your view without tint or if you want to let more light in.
The remainder of this post is, primarily, focusing on operable window coverings. Let’s be honest here; they’re universally more beautiful, the adjustability is a key benefit, and they give you a much wider variety of options.
Option 1: Cellular Blinds
Cellular shades are blinds with a honeycomb-style cross-section. They are typically a single pleated material, using air pockets to help insulate the rest of the room from the differing climate outside.
They are some of the most energy-efficient kinds of blinds out there, and their simple construction allows them to be made out of a variety of different materials, to fit with nearly any décor and style combination. The most efficient cellular blinds are installed with tracks on either side of the window, creating a close barrier to the window and preventing the most energy transfer. They may also be retractable to either the top or the bottom, for added flexibility.
Option 2: Window Quilts
Window quilts are exactly what they sound like: a thick fabric quilt, installed on a roller and fitted to the window. Because they are thick, dense fabric, they have a high insulative capacity and are very good at preventing energy transfer into or out of the building. They are, however, also extremely opaque, and will block all light as well as energy transfer.
While window quilts can be very effective at maintaining building energy efficiency, they tend to be somewhat old-fashioned in appearance, and some people don’t care for the look of a quilt – traditionally a bedding item – placed in a window. They can also require a lot of space for their roller above the window, which can be bulky and out of place.
Option 3: Roman Shades
Roman blinds are an ancient design of window covering. They typically consist of a pane of fabric strung through with cords, to raise or lower the blinds like you would with traditional blinds. Some modern roman blinds may be similar to roller blinds, while others are looser and have a more flexible curtain-like look.
Unfortunately, most roman blinds are more for minor light control and for decorative purposes. They tend to be made of a thinner fabric that does not provide much insulation. As such, they are best for light control, for décor, and of course, privacy. Some roman blinds can be made with heavier fabrics for greater energy efficiency, but they will still likely underperform other styles of blinds solely in terms of energy transfer.
Option 4: Traditional Blinds
Everyone is familiar with simple blinds, which can be found for a low cost at any hardware store. There are, however, quite a few different kinds of blinds.
These use wide horizontal slats that can be adjusted to varying angles, as well as pulled up and out of the way completely. They can let in a lot of light, or block it nearly completely, and their energy efficiency depends on both their position and their material.
Roller blinds are a roll of fabric or other material (such as woven wood) that can be rolled up and down. They only have two modes of operation, and cannot be adjusted for different light levels beyond that simple adjustment. They may be thin enough to be little more than a privacy screen, or thick enough to be full blackout blinds.
Panel blinds have a lower profile and are similar to curtains, in that they are often vertical and slide to the side away from the window rather than up or down. They function similarly to curtains in terms of energy efficiency, though it also depends on the material they’re made out of. They can be decorative printed fabrics, blackout materials, and anything in between.
Vertical blinds are tall, semi-wide slats made of plastic, PVC, wood, or other material. They can be slid to the side out of the way, as well as rotated to let in varying levels of light. They are very similar in energy efficiency and material profiles to Venetian blinds, only vertical rather than horizontal.
There are other blinds styles as well, such as zebra-vision blinds with double-layer control, adjustable visage blinds, and one-way silhouette blinds. All of these have their insulating properties and R-values, so picking the right balance between appearance and functionality will be a matter of personal choice. Blinds can also be made as outdoor window coverings.
Option 5: Shutters and Shades
Roller shades and shutters are an external, rather than an internal, form of window covering. Shutters can range from decorative wooden slats to storm shutters meant to protect window glass from inclement weather events. They are often vinyl. Shutters are often only adjustable in the sense that you can open and close them, while shades can be raised or lowered just like roller blinds, only from outside rather than inside. Shutters can also be decorative. Some shutters are designed with a security element as well and can be locked, as well as being constructed out of heavier-duty materials to prevent intrusion or damage to windows.
Shutter shades can be adjusted in angle to a certain extent, though some have a more limited range of movement than most blinds. Again, there are many different styles and constructions of shutters and shades, so there’s likely a good product waiting for you to suit your needs – if you can find it.
Option 6: Awnings
Awnings are window treatments that can also shelter some part of the area outside of the windows. They serve more as light control than as climate control, however, as they do not prevent or inhibit air circulation around windows, so they freely allow heat transfer. The only way they provide more energy efficiency is by reducing direct sunlight that would otherwise get into the home via the windows.
Awnings can be fixed or adjustable, flat or curved as a pram cover, and made of fabric or metal. They are generally not a replacement for other window coverings, but rather an addition.
Option 7: Window Film
Window films are, aside from non-adjustable shutters and awnings, the only inoperable window treatment on this list. Typically, they consist of an adhesive layer applied to the windows, followed by a film that offers UV protection, additional insulation, and tint. Different levels of tint and different levels of insulation come with different kinds of film.
Window films are popular in certain window positions that would otherwise get too much direct light. They are also often used in commercial buildings where glare and UV light can be a problem. They are, however, permanent or nearly permanent, and cannot be easily adjusted.
Positioning and Other Considerations
Depending on the style of window covering you want to install, you may have specific considerations worth keeping in mind.
Curtains need to be installed close to the wall and window. If there’s a large space between the curtains and the window, more air can circulate between the window and the rest of the room. This air circulation also transfers energy, moving heat in or out, reducing the energy efficiency of the curtains.
Screens may be cited as a way to reduce energy transfer from the sun, but they’re typically not insulative at all, and their minimal footprint has very little energy-reflective capabilities. A window screen can be essential for keeping insects out while allowing air through, but it won’t do much to affect energy transfer.
Solar window coverings come in a variety of different levels of opaqueness. The more opaque they are, the more energy they will block, but the more light they will block as well. If you don’t want to block as much light, you won’t block as much energy either. That said, some modern light shades can still block quite a bit of UV energy.
You may also want to consider the R-value of any window covering you choose. R-value is the rating for insulation of a material. For window coverings, this typically ranges from 0.9 to 3.0, with the higher number being the more insulation it provides. Certain kinds of window treatments, like cellular blinds, can be as high as 5.0.
Above all, you likely want to make a choice that fits with your overall décour, the look and feel of your building, and your goals. To that end, we recommend discussing your unique situation with our experienced team to choose the best window coverings for your rooms.
Do you have any questions for us? Would you like a recommendation on an energy-efficient option? Drop us a line on our contact page, or simply give us a call! We have a lot of experience with energy-efficient window coverings and are happy to help you.