How to Insulate Single Pane Windows

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When the weather turns cold, it’s a good idea to insulate single-glazed windows in period homes. By installing window insulation, you may reduce your heating needs and save money. Everyone in the house will be relieved that they won’t be greeted by a chilly draft when they first open their eyes in the morning.

The question is, how can you add insulation to single-paned windows? You can choose from a number of different window insulation methods. Some of the insulation methods are easy and inexpensive, while others are more expensive but will last a long time.

Let’s learn how to inspect your windows for drafts before we dive into window insulation methods. There may be no need for insulation on some of your windows, while others may require a combination of methods.

Checking Your Windows

The windows that need insulation can be easily identified using one of several straightforward methods:

The feel test

The feel test entails merely circling one’s fingers around the perimeter of the window frame in an effort to detect the presence or absence of air leakage. On blustery or chilly days, the air can more easily be felt.

You should insulate a window if you can feel drafts flowing through the frame.

Expert advice: wet your finger and run it down the frame to clean it. This will increase your finger’s sensitivity to cold air, allowing you to more easily notice drafts.

A light check

To perform a light check, you can either wait until a sunny day or use a flashlight. Of course, if the windows are located on higher floors, utilizing a torch can be difficult; nevertheless, if you have a courageous friend to help, put them to work.

The concept is straightforward: if sunlight enters the room via the window frame, the latter should be covered. The third option is the most challenging, but if you’re lucky enough to have a sunny day or a courageous friend, it can work!

A smoke check

The smoke test works regardless of temperature, so there’s no need to find a courageous companion. Put out the lights and sneak around the window sill with a candle. A hole needs to be fixed if the candle smoke is being pulled into the frame or if it suddenly changes direction. Incense sticks are also popular for this purpose because they produce more smoke.

If you take your time and use the three techniques provided here, you should be able to determine which of your windows require insulation. Let’s talk about ways to make your windows more energy efficient.

How to Insulate Windows: Solutions for Short-Term Window Insulation

During the winter months, there are a number of temporary solutions for insulating your windows. Most of these won’t even keep the windows from fogging up for more than a single winter. However, they are inexpensive options that don’t require a lot of DIY expertise to implement.

The first winter in a period home should be manageable with these insulation techniques. After that, you should investigate the permanent insulation options presented below.

Foam Rubber Window Insulation Weather Stripping Tape

This tape can be applied straight to the window frame and will create a tight seal. Very little effort is required to apply it, and careful application may allow you to continue using your window. This tape won’t completely prevent drafts from entering, but it will reduce them significantly.

This procedure only works if the glass and frame of the window are spotless. First, clean the glass thoroughly with a damp cloth, and then let it dry fully before applying the weather sealing tape. Be very careful when removing this tape; doing so has caused the paint to peel for several homes.

Fill Cracks in the Glass

Using weather-seal tape, you can prevent small breaches in your windows from widening as a result of wind and rain.

To keep the air from leaking through the crevices, you can use weather-seal tape, which can be found in most hardware stores and will last for months. Nail polish works just as well for this purpose. Unless you’re going for a funkadelic look, clarity is key.

You’ll need several coats of nail paint on each crack, but the end result is well worth the effort. If you take your time applying the nail polish, no one will ever know it’s there. However, the nail paint will fade after a few months.

Naturally, both solutions are only temporary. If your window is broken, it needs to be fixed immediately because the damage will only get worse with time. Even so, with a few tweaks, you might be able to survive the cold season.

Window Insulation Film

Insulating film for windows is a great way to keep the warm air inside and the cold air out. This window film is widely available and cheap at most home improvement stores.

The window film can be easily installed with a pair of scissors and double-sided tape. You can use a hairdryer to help seal the window film. Doing so will form a tight fit between the film and the glass.

Window film is a great choice, but it might be difficult to find in the winter. Bubble wrap is an alternative to traditional insulation materials that can be used in a pinch. Unlike the insulation film, bubble wrap can be placed on the window in the same manner and serves the same purpose.

Select bubble wrap with larger bubbles if possible. In most cases, this is more insulating than bubble wrap with tiny bubbles.

Simply peel away the tape and get rid of both of them. Stickiness left behind by the tape can be removed with rubbing alcohol or a degreaser. Bubble wrap can occasionally leave a stain behind, but this is quite uncommon.

In most cases, window film will not leave any residue behind. While these options may reduce the amount of natural light entering the home, they are among the most effective temporary insulating measures for windows.

Curtains and Blinds

Blinds or drapes? Sure, why not both? Adding an extra layer of insulation is a terrific method to keep the cold air out of your home. Although it does provide a barrier, this solution does not insulate your windows for the winter and should be used in conjunction with another option from this list.

You can also prevent the cool air from reaching you by installing blinds and curtains (thermal curtains and cellular shades are the best options for this). But it will get inside your house nevertheless, and that could mean trouble with mould and wetness in the spring.

Long-Term Insulation Solutions for Windows

The temporary insulation measures for the windows up above may get you through one cold season. You may then either enjoy your new blind and curtain set up or clean up any sticky residue. However, there are some permanent answers to this problem. Though more costly, these insulation options ensure peace of mind forever after they have been put in place.

We recommend double or triple glazing as the most effective and long-lasting window insulation. It’s the most expensive option, but it also offers the most bang for your buck.

You can completely seal off your home from the outer world with nothing more than bubble wrap, shutters, and adhesives. Double-paned sash windows will make a huge difference in the temperature regulation of your home.

Double glazing is the most effective method of insulating windows. You should reconsider the possibility of installing double glazing on your windows. Many of SashWindowRefurbish’s clients have had this very thinking, however, we routinely perform window repairs that other businesses claim are impossible.

If you’re looking for a long-lasting insulation solution, like double glazing, secondary glazing or draught-proofing, then get in contact with SashWindowRefurbish immediately.

Secondary glazing unit

Keep curtains open during the day – free

It is tempting to shut the blinds or curtains when the temperature drops, but doing so can actually make a room chillier at night.

Keep curtains open during the day, especially if the rooms receive direct sunlight. Beds, couches, furniture, and upholstered items are warmed by the sun’s rays via the windows since they are made of insulating material.

According to the experts: “A room with plenty of sunlight during the day can warm up quicker than one with no sunlight at all.” When the sun goes down, draw the drapes to keep the warmth in.

Use bubble wrap as window insulation for less than £5

It might be challenging to maintain a comfortable indoor temperature when using single-paned windows.

The experts suggested employing the “bubble wrap” trick to stay warm during the winter. They suggested using bubble wrap as a simple and inexpensive option. The tiny air pockets in bubble wrap make it an effective insulator.

Since plastic is used as the foundation, it heats up quite fast and acts as a great insulator. The bubble wrap should adhere to the window if you sprinkle it with water. You will be thankful for it when the temperature drops.

Last Thoughts

The aforementioned temporary insulation measures are ideal for those who have recently moved into a historic home and are concerned about staying warm during the winter. They are also ideal if you want to put off getting double-paned windows until spring. All of these insulation techniques are temporary, as we’ve already mentioned, and some of them can even alter the look of your home.


When to insulate your windows?

Before the winter weather sets in, it is best to insulate your windows. During this period, it can be difficult to discern which windows require protection. However, the smoke test described above is a reliable method of determining which panes of glass should be insulated.

The amount of heat wasted through standard windows is shocking. Windows can cause a home to lose as much as 30% of its heat. In the warmer months, only around 24% of the sunshine that passes through typical double-pane windows is converted into heat.

How can I improve the energy efficiency of my windows with a single pane?

Put up thick drapes to block the cold air outside. When the sun is shining in the house, close the curtains to block out the light. Caulk inside and outside your windows should be checked on a regular basis for signs of wear and tear. Replace any caulk that has faded or cracked with new caulk.

How effective is it to use bubble wrap on windows?

In the winter, bubble wrap is commonly used to insulate greenhouse windows, but it also appears to be effective for home windows. It functions well with or without thermal or standard window coverings.

It’s useful for both square and octagonal windows, for which insulating shades can be hard to come by.

About the author

Glen Ramsey, who presently holds the positions of customer support and content manager, is a cherished member of the Sash Window Refurbish team. He is in a unique position to provide advice on all questions pertaining to the renovation of historic windows because he has a wealth of experience in all elements of window renovation, dealing with clients regularly and assisting them in choosing the best window-related course of action. He oversees the creation of information for all of our platforms in his capacity as content manager, including web content and other materials. Glen has witnessed the whole gamut of Sash Window Refurbish's window restoration activities, from our work on significant listed Georgian homes to a wide variety of smaller-scale private residential projects.


My technician Andrew replaced all my sash windows that had rotten sills. Accessing the rotten sills was not an easy task. He explained to me what needed to be done in order to fix the problem. He is a great person and I’m happy that he was the one who did the job. He is reliable, tidy, friendly and very professional. I highly recommend him.



I hired Andrew and Alex a while back to repair my damaged sash windows. They were was very considerate and very patient as he did his job. A few days ago, I had another problem with one of my sash lock keys and I called him again to come and fix the problem. I’m very impressed that Liam responded quickly and he not only fixed the problem but he also gave me a spare key. What a great after sales service!

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Alex did a great job in fixing windows in our terraced house. The windows were broken, frames damaged and the wood was also rotten. Alex's job was high quality and he did it pretty fast. I was also very impressed that he was considerate of my son’s asthma condition and maintained cleanliness. Top work.



Andrew just recently replaced three sash windows in my Edwardian house. He also repaired and replaced some sills and draught proofed three windows. In addition to that, he also did some carpentry work. What I like the most about Liam is that he did a clean job. He is very professional and always updated me about the timescales and costs. He also did his job with minimal disruptions. I highly recommend him.

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