Why choose Avenir Renovations?
Main types of house extensions
This first part explains the main types of house extensions to understand which solutions fit your specific needs.
Types of house extension
- Side extension: enlargement at ground level or upper floor towards the outside, ideal for adding a living room or an office.
- Vertical extension (raising): adding a level or half-level above the house, relevant if you lack ground space.
- Wood frame or modular extension: quick to implement, often prefabricated, and customizable.
Extension of the roof or converted attics: enhancing the areas under the slope without major external modification.
Steps of the house extension project for French-speaking Switzerland
Here are the main steps to follow, from the initial analysis to the final reception, to ensure the success of your house extension.
Structural work
Structural work constitutes the fundamental step of your extension, ensuring the solidity, structure, and protection of your construction while integrating essential elements for comfort and energy performance.
Excavation and foundation work are carried out to prepare the ground, whether for a lateral extension or an elevation. They help reinforce the existing structure if necessary.
Walls are constructed according to the chosen method, such as concrete, brick, or wood frame. This step ensures the solidity and durability of the extension in the long term.
The framework is installed with care, followed by the installation of the roofing. This step is particularly crucial for elevations and attic development.
Openings such as windows and doors are installed with precision. At the same time, thermal and acoustic insulation as well as joinery ensure comfort and energy performance.
How much do house elevation works cost?
| Project stage | Indicative cost per m² (excluding VAT or subsidies) |
| Architectural study | CHF 200 to CHF 400 |
| Major work (structure, framework, roofing) | CHF 2,500 to CHF 4,500 |
| Finishing work (insulation, networks, partitions) | CHF 1,500 to CHF 2,500 |
| Finishes (coverings, carpentry, painting) | CHF 1,000 to CHF 1,800 |
| Administrative fees and permits | CHF 5,000 to CHF 15,000 |
Example for a 50 m² elevation:
- Studies: CHF 10,000
- Major work: CHF 125,000 to CHF 225,000
- Finishing work: CHF 75,000 to CHF 125,000
- Finishes: CHF 50,000 to CHF 90,000
- Permits and procedures: CHF 5,000 to CHF 15,000
Estimated total: between CHF 265,000 and CHF 465,000 for 50 m²
Elevation works cost on average between CHF 5,300 and CHF 9,300 per m², including studies, major work, finishing work, finishes, and administrative fees. For 50 m², the estimated total budget ranges between CHF 265,000 and CHF 465,000.
Closed and Covered / Finishing Work
This phase includes all the essential work to ensure waterproofing, interior comfort, and the finishing of your extension, while complying with current energy and technical standards.
Waterproofing, Thermal and Acoustic Insulation
Waterproofing is carefully implemented, accompanied by thermal and sound insulation. This work complies with Swiss energy standards, such as Minergie, to ensure comfort and energy efficiency.
Plumbing, Electricity, and Ventilation
The plumbing, electrical, and ventilation networks are installed. This includes the installation of outlets, devices, and mechanical ventilation systems (VMC).
Floor Screeds, Partitions, and Ceilings
The floor screeds are completed, partitions are erected, and ceilings are installed. These steps create livable spaces and define the different interior rooms.
Floor and Wall Coverings
Coverings such as tiles, parquet, paint, or wall tiles are installed. They enhance both the aesthetics and functionality of the interior surfaces.
Finishes
The finishing work includes the installation of baseboards, hardware, recesses, and woodwork. These details provide a polished touch and a complete finish to the project.
Work Acceptance
Final inspection, resolution of any reservations, handover of keys, compliance verification, and transfer of warranties. At this stage, a final quality check is necessary to ensure your satisfaction.
Tips to Optimize Your Extension
To successfully complete your extension and manage your budget, here are some essential tips that will help you optimize your work while ensuring quality, durability, and energy performance.
Leverage Grants or Tax Assistance
Depending on the cantons, financial or tax assistance is available for energy renovation or Minergie constructions. These grants can significantly reduce the overall cost of your work.
Insulate Well from the Design Stage
Integrating good insulation from the design phase helps avoid high energy expenses in the long term. It also improves interior comfort and the overall performance of the building.
Choose Materials Suitable for the Swiss Climate
Opt for materials suitable for the local climate, such as Swiss wood, moisture protection, and high-performance glazing. These choices ensure durability and efficiency against weather conditions.
Keep a Construction Log
Maintaining a rigorous construction log with meeting notes, work records, and tracking of unforeseen events helps better manage the budget. This tool facilitates management and communication among stakeholders.
Engage Certified Local Professionals
Work with BSA architects and recognized local companies. Check the construction liability insurance and the ten-year warranty to ensure quality, safety, and longevity of your work.
FAQ – Frequently Asked Questions
How long does a house extension or a raise take?
The timeframe often depends on the type of extension and the size of the project. For a 50 m² raise, you generally need to allow between 6 to 9 months, excluding administrative processing time (which can last 2 to 3 months depending on the canton).
Is it mandatory to hire an architect?
In Switzerland, cantonal regulations may require it depending on the added surface area. Even if it is not mandatory, the involvement of an architect ensures compliance, energy optimization, and added value to your project.
What materials should be prioritized for good longevity?
Certified Swiss wood (PEFC or FSC) for the framework ensures durability and insulation. Concrete or brick remains common for load-bearing walls. For roofs, prioritize materials suitable for snow and local weather conditions.
Should we plan for dismantling or demolition steps?
In the case of extensions attached to an existing building, modifications may be necessary (partial demolition of walls, roof modifications, asbestos removal). A preliminary study will identify this.
How to manage unexpected budget issues?
It is recommended to set aside a provision of 10 to 15% of the total budget for contingencies: foundation discoveries, technical complications, plan modifications, integrated furniture, etc.
What happens once the construction site is finished?
After completion, you receive a certificate of compliance. You must then proceed with a possible registration with the land registry if the geometry of the building has changed, and insure your new surface according to local standards.
Does my home insurance cover the extension during construction?
Construction liability insurance covers damages caused to third parties during the work, but you need to check your home insurance contract if it offers temporary extension during construction. It is essential to take out dedicated insurance or an extension through the project manager.
Can we continue to live in the house during the work?
Yes, but certain phases may generate noise and dust (structural work, roofing). If the extension significantly impacts internal circulation, it may be preferable to arrange temporary accommodation based on your tolerance level.
Make a custom house extension in French-speaking Switzerland with Avenir Rénovations Suisse
This guide provides a clear and detailed overview of each step of a house extension or raise project in Switzerland. You will find the types of possible extensions, key steps from feasibility to finishing, an overview of costs, as well as tips to optimize your budget and successfully complete your project. With support from a qualified local professional, you can transform your home while ensuring performance, comfort, and durability.
For more personalized information or to discuss your project, the team at Avenir Rénovations Suisse is at your disposal.
