Discover what a thermal break is

The best way to insulate your home, reduce heating bills, and reduce condensation-related moisture problems is to install windows with thermal breaks. This system integrates insulating material into the metal profiles to stop heat transfer at its source, blocking the passage of outdoor cold and retaining heat indoors without overloading your heating system.

If you notice that your home cools down very quickly as soon as you turn off the radiators, in some cases the problem is not in the thermal insulation in the walls, but in old windows through which all the energy escapes. In addition to this huge hidden expense, old windows often “weep.” This annoying effect creates puddles of water that eventually damage the paint and cause mold to appear in the corners.

Replacing these old frames and ensuring good perimeter sealing solves both problems at the root, delivering direct savings every month and making your home better insulated. 

What Exactly Is a Thermal Break in Windows?

A thermal break is an insulation system that inserts a piece of nonconductive material, such as polyamide, between the exterior and interior sides of a metal profile to block the passage of cold or heat.

Traditional aluminum is an excellent thermal conductor. In winter, the aluminum frame absorbs the cold from outdoors and transfers it directly into your living room. This continuous transfer of energy is what we call a “thermal bridge.”

To prevent this, manufacturers divide the window profile into two parts (the exterior and the interior) and place a piece of reinforced hard plastic (polyamide) between them. Since plastic does not conduct temperature, it effectively blocks the cold coming from outdoors. Thanks to this system, aluminum windows achieve a very high level of energy efficiency.

How to Tell Whether a Window Has a Thermal Break

To find out whether a window has a thermal break, open the sash and look for a strip of black or gray plastic in the middle of the metal frame. You should also check whether the inner profile feels very cold to the touch in winter.

At first glance, an old profile and a modern one may look identical when the window is closed. If you have just moved in or want to check the quality of your windows, you can do it yourself in a couple of minutes using these practical methods.

The Touch Test

On a cold day, touch the wall of the room and then immediately place your hand on the inner metal frame of the window. If the metal is almost as cold as the outdoors, the window has no thermal break. If it feels moderately warm and similar in temperature to the wall, it does have a thermal break.

Visual inspection of the frame

Open the window fully and look at the edge of the frame. On an old window, you will see a single continuous piece of aluminium. 

If it has insulation, the frame will look like a sandwich: you will see the outer metal, a strip of rough plastic in the centre (usually black), and the inner metal.

Checking for condensation on the panes

If, when you get up in the morning, you find the frames or panes covered in drops of water, it means that the warm air from the heating is coming into contact with very cold metal. A well-insulated window will not develop condensation on its surface if you ventilate the home normally.

What role does glass play in window insulation?

Glass is just as important as the frame when it comes to insulating a home, since a thermally broken window will lose much of its effectiveness if it is fitted with basic or poorly chosen glass.

We often focus only on the frame material, but the largest surface of a window is usually the glass. Therefore, if you really want to improve your home's thermal comfort, you should assess the complete unit: frame, glass, internal chamber, and installation method.

Double glazing is the most common starting point for energy-efficient windows. It consists of two panes separated by an air chamber that reduces the transfer of cold and heat. The better the chamber and the more suitable the glass, the more stable the indoor temperature will be.

Low-emissivity glass is also available, designed to reduce heat loss in winter. This type of glass helps maintain the temperature for longer, so the heating system does not have to work as hard to restore lost heat.

In very sunny areas, it may be worth choosing solar-control glass. These panes reduce excessive heat entering in summer, which is especially useful in living rooms with large windows, enclosed terraces, or south-facing rooms.

If you also have exterior noise, choosing a good frame alone is not enough. In that case, the best option is to combine a thermal break with acoustic laminated glass, which helps reduce disturbances caused by traffic, neighbours, bars, or busy areas.

The big dilemma: PVC or thermally broken aluminium

Choosing between PVC and thermally broken aluminium windows depends on your budget, the size of the windows, and the climate in your area, as both materials currently offer excellent insulation.

This is the most common question when renovating. Years ago, plastic provided insulation and metal did not, but technology has narrowed the gap considerably. Each material has specific practical advantages that you should consider before buying.

PVC windows

PVC is a plastic, so it does not naturally conduct cold and does not need extra components for insulation. It is the most recommended option for mountain areas or very cold climates, and is usually somewhat more affordable. It also does not rust and is easy to clean with soap and water.

Thermally broken aluminum: structural strength and aesthetics

Aluminum is much more rigid and stronger than plastic. This strength makes it possible to manufacture very slim frames that let in more natural light, which is ideal for large windows or floor-to-ceiling sliding doors. 

It also offers more modern finishes (such as textured profiles or matte black) and handles the expansion caused by summer heat perfectly.

Verdict: which material to choose according to your needs

Choosing one material over another depends on your needs. If you have a limited budget and your priority is insulating a regular apartment from the cold, PVC is your best option. On the other hand, if you're going to install large windows, prefer very slim frames, or live in an area with very hot summers, thermally broken aluminum is exactly what you're looking for.

That said, keep in mind that good windows are sometimes not enough. If your home gets excessively cold or hot and you're considering taking things a step further, visit our blog. There you'll find very practical ideas for insulate the roof and the walls from the inside.

How to choose windows according to your area's climate

To choose the right windows, you should adapt your choice of profile and glass to the exact needs of your climate and surroundings:

• Cold areas: The goal is to retain heat. Invest in low-emissivity glass, good double glazing, and flawless sealing.
• Warm areas: To prevent the house from overheating, choose solar-control glass and rely on exterior systems such as awnings or shutters.
• Humid areas: The key to preventing condensation is to combine a highly insulating profile with a daily ventilation routine.
• Noisy areas: If you live near heavy traffic or a noisy area, you need to combine a high-quality profile with acoustic laminated glass and a completely airtight installation.

Why a good profile is useless without perfect sealing

Installing the best window on the market is useless if the installation fails, since air and moisture will enter through the poorly sealed joints between the new frame and the wall.

Many people spend money on triple-glazed windows and still feel cold because of poor installation. The perimeter gap around the window is the weakest point. In the past, it was filled with plaster or mortar, but these materials crack with temperature changes and let drafts through.

To ensure good insulation, installation requires the use of professional sealing products:

• Fill large gaps with polyurethane foam expanding foam, which penetrates every gap and forms a barrier that keeps air out.
• Finish the exterior and interior joints with polyurethane putty or silicone neutral, elastic materials that withstand the building's movement without breaking.

How much can you save by replacing your windows?

The exact savings from replacing your windows will depend on your home and climate, but the benefits of this renovation can always be summarized in these points:

• Lower energy bills: By retaining heat in winter and keeping it out in summer, your heating and air conditioning will have to work much less.
• Greater everyday comfort: Uncomfortable drafts and cold rooms disappear, achieving a stable temperature throughout the house.
• The complete system is the key: For insulation to work and for your money not to go to waste, a good frame must always be paired with suitable glazing and perfect sealing.
• It is an investment, not an expense: Beyond the initial price, replacing your windows is a long-term improvement that increases your home's durability and your quality of life.

Common mistakes when choosing windows with a thermal break

Replacing windows is a major investment, but when you are in a hurry or looking for the lowest price, it is easy to make mistakes. To make the investment truly effective and get the most from your money, avoid these classic mistakes:

Combining a high-end frame with basic glazing

This is the classic mistake. There is no point in paying for the best thermal-break system on the market if you then choose basic glazing. Keep in mind that the glass takes up almost the entire surface of the window; if it fails, the insulation loses much of its effectiveness.

Choosing the wrong opening type

Traditional sliding windows are extremely practical because they do not take up space when opened, but when it comes to insulation, they are the weakest option. If you want a completely airtight closure that keeps the cold out, casement or tilt-and-turn windows generally provide a tighter seal.

Ignoring the sealing

You can buy a high-performance window, but if installers adjust it poorly to the wall opening, you will have air, moisture, and outside noise infiltration. Impeccable installation with quality expanding foams and silicone sealants is just as important as the window itself.

Thinking they maintain themselves 

Energy-efficient windows are highly durable, but they are not magic. Giving the seals a quick check, lubricating the hardware, and checking the silicone from time to time will help you avoid problems and keep them working like new for years.

Frequently asked questions about window enclosures and thermal insulation

The most common questions when replacing window systems usually concern the possibility of improving old frames, the recommended insulation thickness, and whether these windows also protect against noise.

So that you have no doubts when requesting quotes and buying construction materialswe answer directly the most frequently asked questions about window renovations.

Can a thermal break be added to an old aluminum window? 

It is not feasible. Polyamide is not an accessory applied on top or a coating that can be added afterward; it is a structural component assembled inside the aluminum profile during the manufacturing process. 

If your current windows are made of continuous metal, the only technical solution for achieving true insulation is to completely replace the window system.

How thick should the polyamide be to ensure effective insulation? 

A profile is considered to offer efficient thermal insulation for most climate zones from a polyamide strip thickness of 16 millimeters. 

However, in highly energy-efficient windows or those intended for extremely cold environments, this component usually ranges between 24 and 34 millimeters. As a general rule, the wider the polyamide, the greater the thermal resistance of the window system and the lower the energy loss.

Does a thermal break also improve acoustic insulation? 

Yes, it contributes very positively. The polyamide insert acts as a shock absorber that reduces the transmission of sound vibrations through the metal. However, to effectively insulate against exterior noise, the determining element will always be the glazing. 

The optimal technical solution is to combine a well-insulated profile with acoustic laminated glass; this synergy guarantees maximum sound comfort inside the home.

Conclusion: invest in comfort and energy efficiency

Replacing your old windows with PVC or aluminum windows with thermal breaks is the most effective way to insulate your home, save on heating every month, and avoid annoying water condensation.

Keeping windows that let the cold in is throwing heating money away. Whether you choose the functionality and price of PVC or prefer the durability and aesthetics of aluminum, today's market offers solutions that radically improve the temperature in your home.

Remember that the window material is only half the job. Pay attention to perimeter sealing with suitable foams and silicone sealants. If you need to touch up your installations or are looking for tools and equipment high-quality, at Brikum you have everything you need to keep your home at the perfect temperature all year round.