How to achieve good external insulation with wood cladding

Around a quarter of the heat produced in a house escapes through the walls. With heating costs constantly on the rise, effective home insulation has become a crucial priority.

Opting for external insulation with wooden cladding is an economical, aesthetic and environmentally-friendly solution. In fact, this type of cladding helps to reinforce your home's thermal insulation while giving it an attractive decorative appearance. By choosing wood cladding, you can enhance the value of your property, improve its thermal and acoustic comfort, while embellishing and protecting your façade.

In this guide, you'll find all our advice on how to make a success of your external insulation project using wood cladding.

Definition: external cladding

External cladding is a protective layer installed on the outside walls of a building. Made from a variety of materials such as wood, metal or composite, it is designed to improve thermal insulation, protect the structure from the elements and enhance the exterior appearance of the building.

Here is a list of the main types of exterior cladding:

• Wood cladding: This can be solid wood, composite wood or wood chemically treated to withstand the elements.
• Composite cladding : Made from a mixture of materials, such as wood and plastic, it combines the advantages of different materials to offer a durable and aesthetically pleasing solution.
• Fibre cement cladding : Made from cement, cellulose and fibres, it is fire, water and insect resistant, while offering great durability.
• Vinyl cladding : Made from PVC, it is durable, easy to maintain and available in a variety of colours and textures.
• Metal cladding : Generally made from steel, aluminium or zinc, this type of cladding is strong, durable and offers a modern look.
• Stone or brick cladding : Using natural materials such as stone or brick, this type of cladding offers a traditional look and great durability.

Each type of cladding has its own advantages and disadvantages, and the choice often depends on aesthetic preferences, budget and the specific requirements of the building or renovation project.

What is external thermal insulation?

External thermal insulation, also known as ETI, is a method of insulating the external walls of a building to reduce heat loss and improve energy efficiency.

This technique consists of adding an insulating layer to the building's external facade, often in the form of insulating panels covered with a finishing material such as plaster, wood, metal or PVC cladding. External thermal insulation helps to maintain a comfortable indoor temperature, reduce energy consumption for heating and cooling, and improve occupant comfort while reducing greenhouse gas emissions.

Why use external cladding as insulation?

• For effective thermal insulation: External cladding acts as an extra layer of thermal insulation, reducing heat loss in winter and preventing heat from penetrating indoors in summer. This helps maintain a comfortable indoor temperature all year round and reduces reliance on heating and cooling systems.
• To reduce thermal bridges: By covering the entire external surface of the walls, external cladding helps to minimise thermal bridges, the areas where heat can escape more easily. This improves the energy efficiency of the building and reduces temperature variations inside the home.
• For protection against the elements : External cladding offers extra protection against the elements. It protects the underlying structure from damage caused by moisture and weather fluctuations, extending its durability and longevity.
• Easy to install and maintain: External cladding is generally easy to install and maintain. Once installed, it requires little regular maintenance, making it a practical and economical solution in the long term.

Wood cladding: an ecological insulator and a natural material for insulating walls

Wood is a renewable and biodegradable material, making it an environmentally friendly choice for external insulation. What's more, as a natural material, wood has a relatively low carbon footprint compared with other building materials.

Wood cladding: effective thermal insulation with an attractive appearance

Wood is an excellent natural insulator. It helps to keep the building warm in winter and cool in summer. Wood cladding on the façade can therefore help to improve the energy efficiency of the house by reducing heat and cooling losses.

Wood lends a warm, natural appearance to a building. With a wide range of wood species available and the possibility of choosing from different finishes and different types of installation (vertical or horizontal), it offers the opportunity to personalise the exterior appearance of your home according to your aesthetic preferences.

Wood cladding, protecting the façade from the elements

Quality timber cladding is generally treated to resist weathering and insects. This means they can last for many years with proper maintenance, making them a durable option for external insulation. Thanks to its natural weather-resistant properties and ability to regulate moisture, wood cladding not only protects the façade, but also helps to extend the durability and longevity of the entire building.

In short, using wood cladding for external insulation offers a combination of advantages, combining energy efficiency, durability, aesthetics and respect for the environment.

Installing insulation before timber cladding

Installing insulation before timber cladding is an essential step in creating an effective thermal envelope for any building. This careful preparation not only ensures optimum insulation, but also provides additional protection against the elements, while improving thermal comfort and reducing energy costs in the long term.

Before installing wood cladding, it is therefore vital to choose the right insulation for the specific needs of the building, its geographical location and the regulations in force. There are many insulation options, from rigid boards to rolls and sprayed insulation, each offering its own advantages in terms of thermal efficiency, durability and ease of installation. Here are just a few examples : mineral wool insulation, cellulose insulation, sheep's wool insulation, wood fibre insulation, etc.

Wood cladding installation techniques for good external insulation

There are three main techniques for installing wood cladding for external insulation:

• Installation of "add-on" cladding.

The "add-on" technique for insulation with external cladding refers to a process in which the insulation is fixed to the external wall of the building, then covered with an additional layer of cladding material, often called cladding. This method adds an extra layer of insulation to the existing structure without affecting the interior space. In this technique, the insulation can be fixed directly to the outer surface of the walls, then covered with a rainscreen membrane to protect the insulation from damp. Cladding is then installed over the insulation, providing both additional protection from the weather and a decorative aesthetic to the building's façade.

• Installation of "double skin" cladding

The "double-skin" technique involves creating a structure with two external facings separated by a layer of insulation. This method provides effective thermal insulation while maintaining an attractive exterior appearance. In this technique, the first layer of cladding is usually made of structural materials such as concrete, metal or masonry. A layer of insulation is then placed between this first layer and a second cladding layer, often made of more aesthetically pleasing finishing materials such as wood, metal or vinyl cladding.

• Installation of "single skin" cladding

The "single skin" technique for insulating with wood cladding involves fixing the wood cladding directly to the external structure of the building, without adding an extra layer of insulation between the cladding and the external wall.

In this method, the timber cladding acts as both an external cladding and an insulating layer. Although this technique can provide basic insulation, it is generally less thermally efficient than methods that add insulation.

In France, there are a number of grants and subsidies available to encourage the external insulation of homes, including :

• MaPrimRénov': public aid available to all owners and co-ownerships of homes occupied as their main residence and built at least 15 years ago.
• Éco-Prêt à Taux Zéro (Eco-PTZ): This interest-free loan enables you to finance energy renovation work, including external insulation, without paying interest.
• Exemption from property tax for energy-saving work: Some local authorities (communes, départements, etc.) temporarily exempt households that carry out energy-saving work from property tax. The exemption may be total or partial.
• Energy Savings Certificates (CEE): Energy suppliers are obliged to finance actions aimed at reducing energy consumption, including the insulation of homes. They can therefore offer grants or financial aid for external insulation work.
• Local authority grants: Many local authorities offer grants and subsidies to encourage energy renovation, including external insulation. These grants vary from region to region.

We recommend that you contact the relevant bodies, energy suppliers and local authorities, in your country, to find out about the support available and the specific eligibility conditions for each scheme.

The price of external wood cladding insulation ranges from €80 to €300/m². The cost varies according to :

• The installation technique used
• The material used
• The type of building
• The surface area and installation height

How much does exterior wood cladding cost?

External insulation under wood cladding consists of fixing insulation to the external walls and then applying cladding strips for complete insulation.

External insulation under cladding offers a number of advantages :

• Easy to implement
• Quick and easy to carry out renovations or repairs,
• Excellent durability

You should allow between €100 and €300/m² for external insulation under cladding, including installation. This price may vary depending on the type of wood cladding chosen for the project.

To find out about all our timber cladding prices, contact our experts.

For the construction of a wood extension for a detached house, there are other wood cladding options with combinations of wood species and saturators that can be adapted to suit the project and its geographical location.

In conclusion, insulation with wood cladding is an effective, attractive and environmentally friendly solution for improving the energy performance and appearance of buildings. Wood cladding offers a unique combination of natural insulation, durability and natural beauty, making it a popular choice for many renovation and construction projects. If you have a wood cladding project, please do not hesitate to contact our wood experts.