Why choose Avenir Rénovations?
Why choose an accessible rooftop terrace?
Raising a house by creating an accessible rooftop terrace allows you to:
- Increase living space without modifying the footprint, ideal for dense urban areas, allowing vertical expansion without encroaching on the existing land.
- Create usable outdoor space: terrace, vegetable garden, relaxation area, office or gym, a versatile place to fully enjoy your roof.
- Enhance your property with a modern extension, increasing real estate value by 15 to 25%, according to various recent real estate studies.
- Optimize thermal and acoustic insulation by combining high-performance materials, reducing energy costs and improving indoor comfort year-round.
- Modernize the building's aesthetics with a cubic and contemporary design, bringing a renewed architectural style and better integration into the urban environment.
Key steps of the accessible roof terrace extension project
The extension project includes technical study, budget estimation, administrative procedures, architectural design, work carried out by certified craftsmen, rigorous monitoring, final inspection, and post-delivery assistance.
Technical prerequisites for carrying out an accessible roof terrace elevation
Before starting an elevation project, it is essential to carry out several checks and preliminary studies to ensure feasibility, regulatory compliance, and the strength of the existing structure:
Before developing an accessible rooftop terrace, it is essential to consult a study office or a local engineer to analyze the load-bearing capacity of the walls and foundations. If the structure is weak, prioritize a lightweight setup with minimal furniture and light plants. For heavier use, such as a jacuzzi, pergola, or vegetable garden, a concrete slab or reinforced framework is recommended. This step ensures the safety and durability of the rooftop terrace, avoiding any risk of overload and ensuring a good distribution of loads on the existing structure.
The insulation must comply with Swiss standards regarding U-value, ensuring optimal thermal performance. It can be installed as external insulation, using materials such as PIR or rigid wool, or as internal insulation depending on the building's configuration. The vapor barrier is essential to prevent condensation and protect the insulation, especially above wet rooms such as the kitchen or bathroom, thus ensuring durability and energy efficiency.
The waterproofing relies on a welded membrane, whether made of elastomeric bitumen or synthentic material, providing reliable protection against water. It is installed with a slight slope to facilitate the drainage of rainwater. Special attention must be paid to the joints, particularly around the drains, guardrails, frames, and walls, to prevent infiltration and ensure perfect waterproofing across the entire rooftop terrace.
Guardrails are mandatory with a minimum height of 1.10 m, in accordance with the NF P 01-012 standard or its Swiss equivalent. Clearances must be respected, ensuring good circulation and providing suitable emergency access according to the building's category, whether it is an ERP or a private residence. Depending on the area created, a building permit or a prior declaration is necessary, taking into account cantonal and municipal requirements in Switzerland.
How much do accessible rooftop extension works cost?
The cost of an extension varies depending on several factors: area, type of structure, insulation, terrace layout, and site accessibility. Here is an indicative estimate of prices in Swiss francs (CHF) including tax per m², taking these different parameters into account for a more precise quote.
| Type of project | Average price (CHF/m²) |
| Light extension (wood frame, minimal) | 1,500 – 2,000 CHF |
| Standard extension (furnished terrace) | 2,000 – 2,500 CHF |
| High-end extension (greenery, jacuzzi, heavy equipment) | 2,500 – 3,000+ CHF |
Influencing factors :
- Total area of the rooftop terrace
- Chosen supporting structure (wood, concrete, mixed)
- Level of insulation and waterproofing
- Planned amenities (guardrails, coverings, furniture, garden, lighting...)
- Administrative fees (plans, permit submission)
- Site accessibility (cranes, scaffolding, urban constraints)
What is an accessible rooftop terrace?
An accessible rooftop terrace is a flat roof designed to be used as a living or leisure space. Unlike an inaccessible roof, reserved only for maintenance, it allows for the installation of furniture, safe circulation, and complies with current standards. This type of roof is characterized by suitable finishes, reinforced waterproofing, and devices ensuring user safety:
- A reinforced load-bearing structure made of concrete, wood, or steel, designed to support light or heavy loads related to the rooftop terrace setup.
- Optimal waterproofing including a slight slope (1.5–2%), a welded membrane, and a vapor barrier, ensuring effective protection against water infiltration.
- High-performance thermal and acoustic insulation, essential to guarantee the indoor comfort of the new floor as well as that of the existing housing.
- Mandatory safety devices: guardrails ≥ 1.10 m, sufficient clearances, secure access, compliance with NF P 01-012 standards to ensure safety and compliance.
Types of structures for an accessible rooftop terrace
Depending on your technical and aesthetic needs, various options can be considered. Each choice allows for adapting the project to the building's constraints while meeting your expectations for design and functionality:
Wood frame
- Light and quick to install, this method is ideal for existing structures with limited load-bearing capacity.
- Perfectly suited for old buildings and dense urban environments where space is limited.
Concrete
- Robust solution, designed to support heavy loads while offering excellent resistance to weather and wear.
- Perfectly suitable for heavy setups like green terraces, jacuzzis, or pergolas requiring a solid and stable structure.
Mixed structure (wood + metal)
- This solution perfectly combines lightness and stability to ensure a durable and secure structure.
- Allows for creating aesthetic volumes while reducing the overload on the existing building structure.
Your project in Switzerland: why choose Avenir Rénovations Suisse (French-speaking)?
The company highlights its key values, including its commitment to quality, transparency, and respect for deadlines. It also emphasizes the warranties offered, ensuring clients reliable work that meets standards, with personalized support throughout the project.
- Single point of contact: a dedicated Project Manager guides you from start to finish.
- Comprehensive follow-up: each stage of the project is planned and monitored rigorously.
- Administrative support in all cantonal and municipal procedures.
- Certified craftsmen, selected for their local expertise.
- Ten-year warranty and compliance with equivalent Swiss RGE standards.
- Online client space to track project progress in real time.
- Assistance in finding grants, especially for energy insulation or accessible equipment.
FAQ – Accessible rooftop extension
Is a building permit required?
Yes, generally in Switzerland a permit is necessary as soon as the created area exceeds certain thresholds (often 20 m², sometimes 40 m²). Below that, a prior declaration may suffice, depending on the cantons. Avenir Rénovations Suisse handles all the procedures.
What about thermal insulation?
We offer solutions that comply with Swiss values (U-value) and often use external insulation (PIR or rigid foam). A vapor barrier is systematically installed to ensure airtightness.
Can the terrace be vegetated?
Yes, vegetation is possible, provided there is a robust concrete structure and reinforced waterproofing. It is an excellent solution for insulation and aesthetics.
What possible uses for the rooftop terrace?
Garden, relaxation area, office, vegetable garden, small jacuzzi, or pergola depending on the load-bearing capacity and choice of materials.
Are financial aids available?
Yes, especially for insulation, accessibility, or energy-saving works. Avenir Rénovations Suisse can guide you to suitable cantonal or federal programs.
What is the average completion time?
From the initial study to final delivery, expect generally 3 to 6 months depending on the complexity and permits.
Contact Avenir Rénovations Suisse for your accessible rooftop extension project
By choosing the accessible rooftop extension, you opt for a modern, enhancing, and functional solution that meets your needs for space and comfort. Avenir Rénovations Suisse offers you a complete service: technical study, administrative procedures, execution of works, and personalized follow-up.
Contact us today for a free personalized study: our team will assist you in bringing your project to life with peace of mind, in compliance with Swiss standards and deadlines. Your accessible rooftop terrace is within reach!
