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The home extension works provide the opportunity to add an extra room or to make more efficient use of the existing space, while adding real value to your property. In Belgium, expanding your home is also a smart way to improve your daily comfort and the energy performance of the housing. The total project cost depends on several factors: the construction method chosen (timber frame, traditional masonry, metal structure), the land configuration, the desired level of finish, or even the specific technical constraints. Generally, the price of a 20 m² extension ranges between 20,000 and 60,000 €, with amounts potentially higher for more complex projects. With Avenir Rénovations Belgique, discover a clear and detailed estimate of the budget to plan for your extension.
The overall cost of extension works depends on many factors, including the construction method chosen, the materials used, and the desired level of finish. Each project being unique, these elements directly influence the final budget of your extension.
The cost of a 20 m² home extension mainly depends on the construction method chosen. The horizontal extension (extending the existing building) remains the most common. It has an average price ranging between 19,000 and 38,000 €, including labor and materials.
The roof extension is another option, more expensive due to its structural and technical constraints. Its average budget ranges between 27,000 and 60,000 €.
The installation of a veranda also represents an aesthetic and bright alternative. Depending on the materials used — aluminum, wood, or PVC — the cost ranges between 28,000 and 50,000 €.
Finally, the conversion of the attic remains a more economical solution to enlarge the space without increasing the ground area. For a house with 20 m² of convertible space, budget between 6,000 and 16,000 €.
The chosen materials strongly influence the overall budget of your extension. In Belgium, a timber frame construction represents an ecological and efficient solution, with prices ranging between 950 and 1,900 €/m². If you opt for a traditional masonry structure (blocks or concrete blocks), you will need to budget slightly more, between 1,200 and 2,000 € per square meter.
Another interesting alternative, cellular concrete is appealing for its lightness and high thermal insulation capacity, with costs ranging from 1,600 to 2,500 €/m². As for container extensions, modern and modular, they require an investment of 1,000 to 2,000 €/m², excluding adaptation and insulation works. After the visit from our Project Manager, Avenir Rénovations Belgique will provide you with a detailed quote allowing you to accurately estimate the budget for your extension project.
The finishes are an essential element influencing both the final appearance and the total cost of your extension. For a raw version, without interior fit-out or bathroom, budget between 950 and 1,900 €/m². Adding a shower room or bathroom results in a slight increase in the price, which then ranges between 1,100 and 2,250 €/m², depending on the equipment and materials chosen.
If you opt for a turnkey extension, fully finished and immediately habitable, the average cost ranges from 1,200 to 2,500 €/m². This option generally includes complete insulation, electrical installation, painting, and floor covering installation. In the case of a high-end version with an integrated bathroom, the price can reach up to 2,900 €/m². For a clear and reliable estimate, contact Avenir Rénovations Belgique: our experts will prepare a detailed and tailored quote to your needs, budget, and the specifics of your home.
Do you want to gain space and improve your daily comfort? At Avenir Rénovations Belgique, we offer several home extension solutions of 20 m² tailored to your needs and budget. Whether it’s a timber frame extension, a storey addition, or a custom veranda, our experts assist you at every stage of your project, from design to finishing touches.
Choosing a timber extension means opting for a natural, aesthetic, and insulating material, ideal for fast and durable construction. This type of enlargement offers several advantages: a shorter construction time than a masonry extension, excellent thermal performance, and a beautiful visual integration with the existing building.
Our professionals design your 20 m² timber extension while adhering to Belgian standards for insulation and energy efficiency. With a detailed quote, you can anticipate costs and plan your investment with peace of mind.
When your land is limited, a storey addition is a clever alternative to enlarge your home. This technique involves adding an additional floor — in wood, concrete, or steel — while preserving the ground area of your garden.
We handle the entire project: feasibility study, design, structure, insulation, and finishing. The storey addition allows for a perfect harmony with your existing home while enhancing its thermal and acoustic performance. Our teams ensure a quick and compliant execution with current Belgian regulations.
Installing a 20 m² veranda is an ideal solution to enjoy an additional room filled with light. Made of aluminum, wood, or PVC, the veranda adapts to all architectural styles and desires.
Our specialists design your project taking into account:
We also assist you with the necessary administrative procedures and provide you with a clear and precise quote to estimate the total cost of your 20 m² home extension.
In addition to construction, we ensure a complete fit-out of your new living space. Do you dream of a master suite, a home office, or an independent studio? We tailor each project to your desires while respecting your budget and modern comfort requirements.
Our qualified craftsmen select durable and aesthetic materials to guarantee the quality of the final result. With transparent and detailed quotes, you gain a comprehensive view of your project's costs before work begins.
Contact Avenir Rénovations Belgique today to obtain a personalized study and a custom quote for your 20 m² home extension.
To successfully complete your extension project in Belgium, several essential phases must be followed. At Avenir Rénovations, we support you at every stage, taking into account your budget, your needs, and the technical constraints specific to your home.
Expanding your living space with a 20 m² home extension is a significant project that requires specialized expertise. To ensure the success of your work, it is essential to surround yourself with true specialists. In Belgium, Avenir Rénovations supports you at every stage, from project design to turnkey delivery.
We provide our clients with a multidisciplinary team of experienced professionals, composed of experts in construction, renovation, and fit-out. From the launch of the project, you benefit from a free visit from a Site Manager from Avenir Rénovations, who is responsible for assessing the feasibility of the extension and guiding you towards the most suitable technical solution for your home.
Following this meeting, a detailed and free estimate is provided to you within 8 days. This allows you to have a clear and transparent estimate of the cost of your project. Request a quote from Avenir Rénovations now to know the price of a 20 m² extension in Belgium.
Extension or renovation projects in Belgium often require municipal permits. Our experts guide you step by step through these procedures to simplify the process.
We handle the urban planning permit application or the prior declaration of works, depending on the nature and size of your extension. Additionally, our advisors can inform you about the renovation and energy efficiency grants available in Wallonia, Brussels, or Flanders, especially if your extension includes thermal insulation or attic fit-out.
Choosing Avenir Rénovations Belgium means benefiting from a global and professional follow-up of your site. Your dedicated Site Manager, a true technical coordinator, plans the interventions of the craftsmen, controls supplies, and ensures compliance with the specifications.
Each step – from structural work to finishing – is monitored rigorously. We ensure the quality of materials, compliance with Belgian standards, and the aesthetic coherence of your extension with your existing building. This way, you enjoy an expanded, durable, and harmonious space.
Choosing Avenir Rénovations for your 20 m² home extension in Belgium guarantees a well-managed project. We commit to meeting the deadlines so that you can quickly enjoy your new space. Furthermore, our pricing transparency policy ensures no unexpected costs.
Your complete and accurate estimate allows you to anticipate each expense with peace of mind. All our work is covered by a ten-year guarantee, ensuring you total protection for ten years.
We do everything possible to ensure your extension combines comfort, aesthetics, and durability.
Also, discover our renovation guide to learn more about the extension techniques used by our teams, and request your free quote today for a personalized estimate.
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The cost of a 20 m² home extension depends on many factors, including the area, the type of extension, and the materials used. The characteristics of the land also play a crucial role in the final price.
A 20 m² extension allows for the addition of a comfortable room or the enlargement of an existing space. In Belgium, the average cost of a home extension is around 1,250 €/m², with a price range varying between 900 and 2,000 € per m², labor included. Thus, for an area of 20 m², a total budget between 18,000 and 40,000 € should be anticipated, depending on the difficulty of the work and the technical constraints of the land.
The nature of the extension significantly influences the total project cost. A side extension with a flat roof of 20 m² costs on average between 18,000 and 38,000 €. A storey addition is generally more expensive, with prices ranging between 27,000 and 60,000 € for the same area.
In the case of a veranda, prices range from 1,400 to 2,500 € per m², or 28,000 to 50,000 € for 20 m², depending on the chosen materials — aluminum, wood, or PVC — and the desired level of insulation.
The materials used directly influence the overall cost. A timber frame extension costs between 900 and 1,900 € per m², or 18,000 to 38,000 € for 20 m². For a construction made of concrete blocks or bricks, prices rise between 1,200 and 2,000 € per m², representing a total between 24,000 and 40,000 €.
Interior and exterior finishes (insulation, coverings, joinery, painting) can also add several thousand euros depending on the quality of the chosen materials.
Foundation work constitutes a significant budget item. On stable ground, conventional foundations generally cost between 5,000 and 10,000 €. However, if the land requires deep or reinforced foundations, an additional cost of 10,000 to 20,000 € should be expected, or even more depending on geotechnical analyses and the nature of the soil.
| Materials and foundations | Estimated cost per m² or total (€) |
| Timber frame | 950 to 1,900 € / m² |
| Concrete blocks | 1,200 to 2,000 € / m² |
| Veranda (aluminum, wood, or PVC) | 1,400 to 2,500 € / m² |
| Cellular concrete | 1,600 to 2,500 € / m² |
| Habitable container | 1,000 to 2,000 € / m² |
| Shallow foundations (stable ground) | 5,000 to 10,000 € |
| Deep foundations (challenging terrain) | 10,000 to 20,000 € |
In Belgium, the average prices are generally comparable to those in France, but can vary depending on the region (Wallonia, Brussels, or Flanders), the local labor, and the energy standards to be met (such as PEB).
