Everything you need to know about building envelope energy renovation

Building energy renovation: an investment for the future

Energy renovation is a major issue in Switzerland. It reduces the energy consumption of buildings, homes and business premises, decreases greenhouse gas emissions and improves the quality of life for occupants. Renovating the building envelope plays a crucial role in achieving these objectives.

---

Building envelope: the starting point for effective renovation

The building envelope, made up of the walls, the roof, the windows and the floor, is the first barrier against heat loss in winter and overheating in summer. A high-performance envelope is therefore essential to guarantee optimal comfort and reduce heating and cooling requirements.

---

What are the different types of work involved in renovating a building's envelope?

The energy renovation of a building's envelope covers several types of work, aimed at improving its insulation and air tightness. Here are the main ones:

---

1. Roof insulation:

• Insulation of unused attics: if your attic is not converted, insulation can be done by blowing mineral wool, spreading roll wool or laying rigid insulating panels.
• External roof insulation (sarking): this technique consists of laying the insulation on top of the existing frame, before laying the new covering. It provides continuous, high-performance insulation.
• Internal roof insulation: the insulation is laid between the rafters or under the roof, which can reduce ceiling height.

---

2. Wall insulation:

• External wall insulation (ITE): the insulation is fixed to the outside walls, then covered with a render or cladding. ITE is very effective and preserves the interior living space.
• Internal wall insulation (ITI): the insulation is laid on the interior walls, which can reduce the living area. ITI is generally less expensive than ITE, but less efficient.

---

3. Floor insulation:

• Insulation of the lower floor over a crawl space: the insulation is laid between the floor joists or on the concrete slab.
• Insulation of the lower floor on the ground: the insulation is integrated into the concrete slab during construction or laid over the existing slab.

---

4. Window replacement:

• Double or triple-glazed windows: high-performance windows considerably reduce heat loss. The choice of glazing type depends on the orientation of the windows and the insulation requirements.
• High-performance frames: the window frames must also be insulating to guarantee optimal performance.

---

5. Improving air tightness:

• Sealing openings: sealing windows and doors limits infiltration of cold air.
• Air tightness membrane: installing an air tightness membrane creates an airtight envelope and limits heat loss through convection.

---

6. Other work:

• Installation of roller shutters or insulating blinds: this equipment limits heat loss in winter and overheating in summer.
• Installation of solar protection: solar protection limits heat gain in summer and improves comfort.

---

Thermal insulation: the key to energy savings

Thermal insulation is the central element of a building envelope renovation. By strengthening the insulation of the walls, roof and floor, you limit heat loss and considerably reduce your energy consumption. Various insulating materials are available on the market, such as rock wool, glass wool, cellulose or synthetic insulation.

---

Energy refurbishment: a global approach

Energy refurbishment goes beyond simple thermal insulation. It covers all the measures aimed at improving the energy efficiency of the building, such as replacing windows, installing high-performance ventilation systems or optimising heating.

---

Subsidies in Switzerland: financial support for targeted or complete measures

In Switzerland, various subsidies are available to encourage the energy renovation of buildings. These subsidies can cover part of the costs linked to thermal insulation, window replacement, the installation of ventilation systems or other energy refurbishment measures.

---

Legal aspect: the new Vaud energy bill

The Vaud energy bill, adopted by the State Council in September 2024, aims to accelerate the canton's energy transition. The objective is to reduce greenhouse gas emissions by 60% by 2030 and to achieve carbon neutrality by 2050 at the latest.

---

Steps for a successful renovation:

1. Energy assessment: carry out an energy assessment of your building.
2. Subsidy application: find out about the subsidies available.
3. Choice of companies: call on qualified companies.
4. Monitoring the work: ensure the work runs smoothly.

---

EDIREX: your partner for renovating the building envelope

EDIREX supports you in your building envelope renovation project. Our platform lets you find qualified and certified companies in your region.