According to Effy, 30% of French people want to carry out energy renovation work. For 69% of them, the objective is clear: to reduce their energy bills. Although windows are often neglected, they contribute significantly to the energy efficiency of a home. How can you improve the insulation of your windows and save energy? The answer in this article!
Windows: what impact on your energy consumption?
Poor quality or poorly insulated windows are a major source of heat loss. On average, windows and doors account for 15% and up to 40% of a home's heat loss.
When they are not very efficient, windows cost more on your energy bill. Drafts, thermal losses, excessive heat, feeling cold near windows… so many inconveniences that are felt all year round.
In order to limit heat loss, it is generally necessary to renovate your old woodwork. This often involves some repairs and, in some cases, replacement with more efficient windows.
Improving energy efficiency: when should you replace your windows?
Replace windows is a sometimes costly project, but necessary to maintain excellent energy performance. Moreover, the age of the joinery is not the only criterion to consider to evaluate its energy efficiency. If we estimate that a window has a lifespan of approximately 15 to 20 years, certain signs may indicate that it must be replaced sooner.
Why change your windows?
Old joinery sees its performance decline over time, which perfectly justifies its replacement. In addition to optimizing energy efficiency, other reasons can motivate the replacement of windows: comfort, energy savings, carbon footprint reduction, etc.
Window replacement: what signs should alert you?
Wondering if it’s time to replace your windows? Here are some signs that should prompt you to consider a replacement:
- You feel cold or drafts near your windows;
- You notice condensation forming regularly on your windows;
- Your windows are cold to the touch;
- Your window frames are warped or cracked;
- You have difficulty opening or closing your windows;
- You carried out a thermal balance and it turned out to be negative.
What materials should you choose for high-performance windows?
The energy efficiency of windows depends largely on the material they are made of. Three options are particularly interesting: wood, PVC and aluminum.
Wood: for a traditional and naturally high-performance window
Wooden windows are excellent thermal and acoustic insulators. Dense by nature, they effectively reduce thermal bridges. Furthermore, wooden joinery is aesthetic, customizable and durable if it is well maintained. Their disadvantage? Wooden windows require more maintenance and are more sensitive to bad weather.
PVC windows: the economical option
PVC is without a doubt the material that offers the best value for money. Easy to maintain, excellent thermal and acoustic insulation, multiple designs to choose from… all at unbeatable prices! On the other hand, this material is not suitable for large windows such as bay windows.
Aluminum: the ultimate resistant material
Aluminum is especially favored in modern constructions for its solidity and finesse. Its fine lines make it a perfect option for large openings and windows with a sleek or atypical design. Aluminum windows are also very resistant to bad weather, and even to the harshest climatic conditions. Thermally, aluminum is much less insulating than PVC or wood. To obtain optimal performance, a thermal break is generally necessary.
Glazing: an essential energy performance criterion
The question of glazing systematically arises when considering investing in new windows. You should know that glazing largely determines the thermal insulation of your windows, and consequently the interior comfort.
The different types of window glazing
Single glazing is the least insulating model, since it only has one pane of glass. Its energy performance is lower and no longer meets current standards.
Double glazing is certainly the most widespread in modern homes. It is composed of two layers of glass, separated by a layer of insulating gas. This type of glazing is both insulating and affordable, which is why it is so popular.
Triple glazing has an additional layer of glass, which allows it to offer better thermal performance. While triple-glazed windows are the most efficient, they also require a larger investment.
What type of glazing should you choose for your windows?
In terms of insulation performance, triple-glazed windows are a safe bet. However, if you have a limited budget, double glazing can do the trick. However, other technical points must be checked to guarantee the energy efficiency of your joinery.
The lower the thermal insulation coefficient, the better the insulation. The solar gain indicates the amount of solar heat transmitted inside. Ideally, opt for windows that can let heat in in winter and protect against overheating in summer.
In terms of safety, choose glazing that is sufficiently impact-resistant. Laminated glazing is generally recommended, as it meets this requirement perfectly. Finally, if you live in a noisy area, plan for at least double glazing with reinforced acoustic properties.
Is there financial assistance available for replacing windows?
In France, public authorities are encouraging the energy renovation of housing in order to combat climate change. Heavily involved in the thermal insulation of a building, the replacement of windows is one of the works eligible for financial aid.
What are the conditions for benefiting from this aid?
To be eligible for subsidies, several conditions must be met:
- Be the owner-occupier or lessor of the accommodation concerned.
- Call on a RGE (Recognized Environmental Guarantor) certified craftsman.
- Comply with the resource conditions imposed.
- Carry out work to improve the energy performance of the home.
Good to know: In some cases, tenants may be eligible depending on the systems and resource criteria.
Aid available for window replacement
MaPrimeRénov' is an aid offered by Anah, intended for all owner-occupiers who wish to carry out energy renovation work. The amount of aid depends on the household's income and the type of work to be carried out.
The zero-rate eco-loan or eco-PTZ is a bank loan to finance the work, the interest of which is covered by the State. To benefit from it, the accommodation must be a main residence and have been built more than two years ago.
The CEE bonus is available to all households, regardless of their income. This bonus is paid by energy suppliers to reward individuals who carry out energy efficiency work. The amount of the bonus is limited to 5% of the amount of the work.
Finally, the VAT reduced to 5,5% concerns labor and materials. Energy improvement work benefits from this reduction, subject to using an RGE-certified professional.