With a multifaceted range of interior applications, thermowood is used for its vivid texture and natural brown tones. It is sustainable and optimal building material. It has high dimensional stability and can be used in varied climatic conditions when suitably treated. It is non-toxic and resin-free, ages well and has excellent thermal insulation. Thermowood stands for thermally modified wood, to cease rotting. It aids in creating a coherent design throughout spaces, where exteriors and interiors can interact seamlessly. Thermowood is also safe against bugs and is structurally safe. The most common species of wood used is pine or spruce, apart from other hardwoods. The world leader in thermowood products is Lunawood based out of Finland. Here are some uses of this wood in interiors.

10 Ways of using of thermowood in interiors - Sheet1

1. Cladding material on walls | Thermowood

10 Ways of using of thermowood in interiors - Sheet2

Since wooden surfaces reduce echoes reverberating through spaces, thermowood can be used as a cladding material on interior walls, owing to its porous nature. It also naturally softens noise with a soft sound-breaking mechanism. Panelling can be fixed horizontally or vertically and even in patterns, creating functional and minimalistic spaces.

10 Ways of using of thermowood in interiors - Sheet3

The first example is Forum Braga, designed by Barbosa and Guimaraes Architects in Portugal. The harmonious white walls get a hint of colour with the wood panelling along with spotlighting. The floor to ceiling glass walls aid in light diffusion making the space seem bigger. How the cladding is fixed is important. The use of the correct fixing materials, the space between fixings and the number of fixings per board are all factors that need consideration. ThermoWood cladding can be fixed using a traditional hammer and nail punch or with a compressed air nail gun. 

2. Sauna and Spa

10 Ways of using of thermowood in interiors - Sheet4

Since thermowood has low conductivity and high stability, it is used in high-steam pressure and moist places like spas and saunas. It is also easy to clean and maintains hygienic levels. It can also be polished to make it feel smooth to touch. Hotel Kaktus by Byko+Maria Gelpi in Spain has thermowood cladding in its powder rooms. Apart from saunas, it can also be used in kitchens.

3. Furniture

10 Ways of using of thermowood in interiors - Sheet5

There are usually additional coatings done on thermowood furniture to retain the properties and appearance.

Sturdy furniture with warm natural tones, giving off a rustic look and scent, creating timeless spaces. It has geometric firmness due to which designers can play around with shapes and materials along with thermowood. Project O by Aleksi Hautamaki in Finland had a ceiling, walls and floors clad with thermowood with customized furniture.

4. Indoor Decks

10 Ways of using of thermowood in interiors - Sheet6

Thermowood can be used to make interior decks. There are a variety of profiles available, which can be oriented accordingly. Thermowood decks generally get weathered and get a silvery-grey patina, unless protected by a stain. It is a great alternative to impregnated timber and other wood varieties.

5. Fixtures | Thermowood

10 Ways of using of thermowood in interiors - Sheet17

Light-weight fixtures such as small lamps could be installed on thermowood. The installation is generally  done with stainless steel fasteners. The support is given following building bylaws and regulations. Air Base Hotel designed by Studio WG3 and ZT Geldner in Austria is an example in which thermowood battens are fixed onto the walls and ceiling continuously. There are many types of battens and battens available depending on the type of look and depth required, accompanied by different types of grooves and knots. 

6. Flooring

10 Ways of using of thermowood in interiors - Sheet8

A natural scent emanated from the flooring since it is heat-treated the same way as coffee beans roasting or smoked foods. The colours of thermowood are homogenous creating warm brown tones. 

7. Thin partition walls

10 Ways of using of thermowood in interiors - Sheet9

Thermowood is employed for making thin partition walls in interiors.

8. Indoor gardens


Thermowood can also be used to make small gardens in interior spaces, housing some indoor plants and seating. The Orange headquarters in Madrid have their office courtyard made of thermowood combining decking, cladding and furniture. Since it is resistant to decay, thermowood container boxes can be used to grow plants.

9. Issues in interior applications


Thermowood tends to change its colour under the impact of light, predominantly TMT or Thermowood Timber.  While light-coloured timber darkens due to light-induced oxidation reactions, daylight results in the bleaching of dark timber or TMT. The darker the TMT, the stronger the TMT will brighten and the more apparent it will be. The surface of TMT flooring can be protected from bleaching with appropriate means. However, light stabilisers that have been developed for native, especially light-coloured timbers are only of limited benefit to TMT. Special agents that provide for the long-term stability of the original colour of TMT are still undergoing testing. In combination with a suitable coating, those additives can also be applied to outdoor uses.

10.Treatment | Thermowood


Thermowood can be painted over, is resistant to scratches and dents and can be sanded over to reveal the original colour. Paraffin oil is used for surface treatment to emphasise the true colour of the wood. Other wood oils and varnishes can also be used for treating thermowood. 


Asmita Kothari is currently pursuing B.Arch at the School of Architecture, VIT University. She is an avid reader and a movie buff, who loves watching architectural and travel documentaries and shows. She believes that ambitious and curious souls make the world a better place.