With the rise in energy prices, the importance of effective energy renovation has never been more crucial. In 2025, households are looking not only to improve their comfort but also to achieve substantial savings on their energy bills. A well-planned renovation can lead to savings of up to 80%. This process first involves renovating the insulation of the walls, followed by evaluation and optimization of the heating system. In this article, we will explore how these steps can transform your home, while benefiting from significant financial assistance and considering recognized companies in the sector such as Isover, Rockwool, or Knauf Insulation.
The basics of thermal insulation of walls
Effective insulation of exterior walls is a key element of energy renovation. The thermal resistance, measured in m².K/W, is the first factor to consider when assessing the effectiveness of insulation. In France, to benefit from the MaPrimeRĂ©nov’ aid, it is imperative to aim for a minimum resistance of R = 3.7 m².K/W. This means that the choice of materials and their thickness are essential.
Choice of insulating materials
Each insulation material has its own characteristics and performances. Here are some examples of common insulators, based on their thermal conductivity (λ) and the thickness required to meet standards:
| Material | Minimum Thickness (cm) |
|---|---|
| Phenolic Foam | 9 |
| Polyisocyanurate Panels | 9 |
| Polyurethane Panels | 11 |
| Expanded Polystyrene | 12 |
| Glass Wool | 13 |
| Rock Wool | 13 |
| Cork Panels | 15 |
| Rigid Wood Fiber | 15 |
In general, the choice of these materials will depend on the available space, budget, and energy performance goals. For example, polyurethane panels, although a bit more expensive, offer excellent thermal performance.
The benefits of extensive renovation
Extensive renovation, or comprehensive renovation, combines several works for greater energy efficiency. This includes insulation work, heating, and ventilation to ensure an optimized habitat. Why choose this approach? Here are the main advantages:
- Considerable savings: By improving insulation, you reduce your energy needs, allowing you to save on your bills. Indeed, it is estimated that a comprehensive renovation can reduce energy consumption by 55 to 80%.
- Increased comfort: Better insulated walls equipped with a high-performance heating system create a pleasant environment.
- Government assistance: Extensive works are eligible for grants, thus reducing the overall cost of renovation projects.
- Enhancement of your property: A well-insulated and economically efficient home is more pleasant to live in and easier to sell.
Optimization of the heating system
Once the wall insulation is completed, the next step is to optimize the heating system. A good heating system must combine performance and durability. This involves choosing suitable technologies such as heat pumps, pellet boilers, or solar thermal panels.
Preferred technologies
Modern equipment on the market, such as those offered by suppliers like Leroy Merlin or Saint-Gobain, provide excellent efficiency. Here are some popular systems for heating:
- Heat pump: Uses renewable energies to heat domestic water or the air in your home.
- Condensing boiler: Ideal for those looking to replace their traditional boiler, offering better efficiency.
- Solar panels: Convert sunlight into energy to further reduce your expenses.
Evaluating energy performance
Before choosing a new heating system, an energy audit is essential. This audit allows for a comprehensive diagnosis of your home to identify areas for improvement and combine energy efficiency with comfort.
An effective audit will help you determine:
- Areas of heat loss
- Heating systems to be replaced
- Opportunities to install renewable energies
Financial assistance for your renovation project
In the face of rising energy prices, the government offers various financial aids to support energy renovations. In 2025, programs like MaPrimeRĂ©nov’ remain essential to reduce your renovation costs and encourage the use of renewable energies.
Main available subsidies
To lighten the budget of your project, here are the aids you can apply for:
| Aid | Description |
|---|---|
| MaPrimeRĂ©nov’ | State aid for energy renovation, amount varying based on your income and type of work. |
| Energy Premium | Discover specific bonuses offered by private companies to reduce your costs. |
| Reduced VAT | A rate of 5.5% instead of 20% on certain supplies and work. |
| Zero-interest eco-loan | An interest-free loan to finance energy-saving work, up to €30,000. |
| Local aids | Varies by region, these aids are accessible through your town hall or your ADIL. |
Meeting eligibility criteria
It is imperative to meet certain conditions to benefit from these aids:
- Hire RGE-certified craftsmen (Recognized as Environmental Guarantee)
- Meet a level of energy performance for each type of work
- Compare offers to maximize your coverage
FAQ on energy renovation
What are the steps of an energy renovation?
The main steps include an energy audit, insulating walls and attics, optimizing the heating system, and ventilation.
What are the most effective materials for insulation?
Materials such as glass wool, polyurethane panels (Knauf Insulation), and phenolic foam offer excellent thermal performance.
What financial aids are available?
Various aids like MaPrimeRĂ©nov’, the Energy Premium, and zero-interest loans can reduce the cost of your work.
Which heating systems are the most economical?
Heat pumps and condensing boilers are economically and ecologically viable choices.
How much does an extensive renovation cost?
A budget between €20,000 and €60,000 should be anticipated, with aids covering up to 90% of these costs.