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Expanding your home is an excellent solution to gain living space, create a new room, or rethink the interior fit-out. In Luxembourg, this type of project can also serve as an interesting lever to increase the value of your property. However, the final amount depends on many parameters: choice of extension type, land constraints, materials, level of finish, or even technical complexity of the site.
On average, a 20 m² extension in Luxembourg represents a budget ranging from €25,000 to €75,000, with amounts potentially higher depending on the specifics of the project. With Avenir Rénovations Luxembourg, find out how much to budget for a home extension of 20 m² under good conditions.
The cost of an expansion primarily depends on the construction method, level of equipment, and technical constraints. Several elements can therefore influence the overall price.
The extension technique is one of the first factors of variation. The horizontal extension (on the ground) remains the most common solution: it offers a good balance between cost and ease of execution. In Luxembourg, its average price ranges from €23,000 to €45,000 for 20 m², including labor and materials.
The storey addition is an interesting alternative when the land does not allow for ground expansion. However, it involves more structural and technical constraints, which increases the budget. For 20 m², the cost generally ranges from €32,000 to €80,000.
The conservatory is appreciated for its brightness and aesthetic appeal. Depending on the materials (aluminum, wood, PVC) and the level of insulation, its price varies between €30,000 and €60,000.
Finally, the fit-out of attics often represents the most economical option, as it allows for the use of existing space. For this type of project, expect to budget around €8,000 to €22,000 depending on the initial condition and necessary work.
The choice of materials directly influences the cost of your extension, as well as its aesthetic appearance and thermal performance.
A wooden frame extension generally ranges from €1,100 to €2,200/m². For a construction in concrete blocks or traditional masonry, the prices are rather between €1,400 and €2,400/m².
Cellular concrete, valued for its lightness and insulating qualities, represents a budget ranging from €1,800 to €2,900/m².
On the other hand, a container extension can be considered, but often requires specific integration, insulation, and finishing work. In Luxembourg, its cost generally ranges from €1,200 to €2,300/m², excluding specific constraints.
After a technical visit, our Project Manager will provide you with a personalized quote to know the exact total cost of your project.
The price of an extension also depends on the level of finish. A so-called "raw" extension, without interior finishes or bathroom, is the most accessible option. For 20 m², you should budget on average between €1,100 and €2,200/m².
If you wish to include a bathroom, the budget increases due to the networks (plumbing, ventilation, waterproofing). The price then generally ranges from €1,300 to €2,600/m².
For a “turnkey” extension, fully fitted out and ready to be lived in, prices range from €1,500 to €2,900/m². This service often includes insulation, electricity, coverings, complete finishes, and all equipment. With an integrated bathroom, the budget can rise up to €3,200/m².
To obtain a reliable estimate tailored to your home in Luxembourg, contact Avenir Rénovations: we support you from the study to the realization, with a clear, structured approach that aligns with your budget.
To create an additional room and enhance comfort, several options are available to you. At Avenir Rénovations Luxembourg, we offer various home extension solutions designed to fit your house, your technical constraints, and your budget. Wooden extension, storey addition, conservatory, or complete fit-out: our teams support you at every stage, from design to delivery.
Choosing a wooden extension means opting for a solution that is both aesthetic and effective, particularly appreciated in Luxembourg. Wood allows for faster construction than a traditional masonry extension while providing excellent insulation due to its natural properties. Our experts design a wooden extension of 20 m² tailored to your home, in compliance with local regulations and current standards. A detailed estimate is provided to anticipate the overall cost and manage your budget.
When the land does not allow for ground expansion, a storey addition is an ideal alternative. It involves adding an additional level, in wood or concrete structure, while maintaining the current footprint of the house. Avenir Rénovations Luxembourg handles the entire project: structural study, material selection, insulation, and finishes. This solution optimizes the available space while ensuring perfect coherence with the existing style and full compliance with thermal and acoustic insulation standards.
Installing a 20 m² conservatory is a particularly appealing option if you want to create a light-filled space. Depending on your preferences, it can be designed in aluminum, wood, or glass, with a modern or more traditional finish. Our teams define your project taking into account orientation, level of insulation, and material choices to ensure durability. We also assist you with administrative formalities and provide you with a personalized estimate to accurately assess the cost of your conservatory.
Beyond construction, we can also design a fully fitted space, ready to use. Parental suite, office, extra bedroom, independent studio: everything is possible according to your needs. Avenir Rénovations Luxembourg offers you a complete solution, with quality finishes, optimized organization, and support from A to Z. You receive a clear estimate to anticipate the total project price and proceed with peace of mind.
Carrying out a home extension of 20 m² is a structuring project that requires real technical expertise. Between design, regulatory constraints, and coordination of the various trades, each step must be perfectly mastered. In Luxembourg, Avenir Rénovations supports you from the first meeting to the final delivery, with clear organization and rigorous follow-up.
To successfully achieve a 20 m² extension, it is essential to follow a precise process, taking into account technical constraints, urban planning regulations, and the budget. At Avenir Rénovations Luxembourg, we support you throughout the project, from the initial study to the final handover, with clear organization and comprehensive monitoring.
Before starting the work, a feasibility study is essential. That’s why we arrange a free visit from our Project Manager to your home. On-site, he examines the house, assesses the existing structure, and advises you on the most relevant solution: ground extension, storey addition, conservatory, or timber frame construction.
This first phase also allows us to anticipate constraints related to insulation, the land, and material choices. A personalized quote is then prepared to provide you with a reliable estimate of the overall cost of your 20 m² extension in Luxembourg.
In Luxembourg, planning regulations vary by municipality. Therefore, it is essential to consult the applicable urban planning documents before finalizing the project design. This verification ensures compliance with authorized limits (height, distances, footprint, facade choices, etc.) and avoids costly modifications once the construction has started.
This process secures your project and facilitates obtaining the necessary permits.
A home extension often requires specific administrative procedures. Depending on the nature of the work, a declaration or authorization may be required. At Avenir Rénovations Luxembourg, we assist you in compiling the necessary documentation to simplify the progress of the project.
We can also guide you towards existing aid solutions if your extension includes an improvement in energy performance (enhanced insulation, joinery, etc.).
Once the project is approved and the permits obtained, the work can begin. Your Project Manager then takes charge of the complete organization of the site: coordination of craftsmen, monitoring of interventions, quality control, and adherence to the schedule.
From structural work to finishing touches, we ensure that the extension integrates perfectly with the existing structure, with optimal insulation and a finish that meets your expectations.
At the end of the work, a complete inspection is carried out to ensure that the extension meets standards, the planned finishes, and the initial requirements. Your Project Manager accompanies you during the site handover and ensures that everything is compliant before the final handover.
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In Luxembourg, the price of a 20 m² extension depends on many parameters: the type of extension chosen, the materials, the level of finish, as well as the constraints related to the land. To obtain a realistic estimate, it is essential to analyze each element of the project before setting a budget.
Even though 20 m² represents a relatively common extension, the cost can vary significantly depending on the difficulty of the project. On average, in Luxembourg, you should budget around €1,500/m², with a range between €1,200 and €2,600/m², including labor. This means that a 20 m² extension can represent a budget between €24,000 and €52,000, depending on accessibility, the existing structure, and technical constraints.
The chosen solution plays a major role in the total price. A classic horizontal extension with a flat roof is generally the most affordable: in Luxembourg, for 20 m², it costs on average between €25,000 and €48,000.
The storey addition, on the other hand, is often more expensive as it requires structural reinforcements, adjustments to the existing roof, and more complex organization. For an equivalent surface area, the average budget is more likely to be between €35,000 and €80,000.
If you opt for a veranda, prices vary depending on the material (aluminum, wood, PVC) and thermal performance. In Luxembourg, the cost per m² generally ranges from €1,700 to €3,200, or between €34,000 and €64,000 for 20 m².
The choice of materials strongly influences the final amount, as do the finishes (coatings, insulation, electricity, heating, etc.). An extension with a wood frame generally costs between €1,300 and €2,400/m², or about €26,000 to €48,000 for 20 m².
For an extension in concrete blocks or traditional masonry, you should budget between €1,600 and €2,600/m², or between €32,000 and €52,000 in total.
Other solutions can be considered, such as cellular concrete or container extensions, but they often require specific adjustments in insulation and finishes.
Foundations must always be included in the calculation. On stable ground, shallow foundations may be sufficient. In this case, the cost is generally between €6,000 and €12,000.
However, if the land presents constraints (unstable soil, slope, humidity, low load-bearing capacity), deep foundations may be necessary. The additional cost can then reach €12,000 to €25,000, or even more depending on the studies conducted.
| Item | Estimated Cost |
| Wood frame | €1,300 to €2,400/m² |
| Concrete blocks | €1,600 to €2,600/m² |
| Veranda | €1,700 to €3,200/m² |
| Cellular concrete | €1,900 to €3,100/m² |
| Container extension | €1,400 to €2,600/m² |
| Shallow foundations | €6,000 to €12,000 |
| Deep foundations | €12,000 to €25,000 |
The cost of a 20 m² extension in Luxembourg therefore depends on many factors. To obtain a precise estimate tailored to your home, your land, and your project, contact Avenir Rénovations Luxembourg: we will provide you with a clear and detailed personalized quote.
