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Isolation is much more than a story
energy saving...

Indeed, agood insulationcanimproveTHEcomfortheat of a building by making it possible to maintain aconstant temperatureindoors, regardless of outside temperature variations. In addition, insulation ofqualitycan alsoreduceTHEnoisefrom outside, which contributes to aenvironmentinterior morecalmeand morerestful. Finally, good insulation canincreasetherevalueof a property by improving itsenergetic efficiencyand hisoverall comfort.


In short, insulation is aprofitable investmentwho can bringmany advantagesbeyond simpleenergy saving.

Liège façade apparent

Exterior Insulation

The external thermal insulation of the walls ensures perfect sealing, eliminates thermal bridges and guarantees uniform temperatures all year round.

OTRA - Isolation sol en chaux-liège

Floor insulation

The thermal insulation of floors and floors will provide additional comfort   and will save money.

OTRA - Isolation Intérieur en bloc de chanvre Isohemp

Interior Insulation

The thermal insulation of the walls from the inside, makes it possible not to modify the appearance of the facade and to provide additional water comfort

OTRA - étanchéité - frais-vapeur - SIGA


Airtightness plays a key role in successful and lasting insulation.

OTRA - Isolation toiture Gramitherm.jpg

Roof insulation

The main calorie losses are through the roof. Up to 60% losses. It is therefore essential to insulate your roof or attic

OTRA - cuvelage à la chaux hydraulique ouverte à la vapeur - Unilit

Building pathologies

Humidity, salts and mold are dangerous and uncomfortable. Solving these problems is crucial for effective insulation.


Ecological and sustainable biosourced insulation

insulationbiobasedis heresolutionecological andsustainablefor building insulation. She uses materialsnaturalsuch as grass fibre, wood wool, hemp or cellulose wadding, all of which are made from materialsrenewable plants.

These materials are not onlyrespectfulfrom the environment, but they also have insulating propertiesexceptionalboth winter and summer. Grass fiber, for example, is an excellent thermal and acoustic insulator, while hemp is also effective in combating humidity and thermal bridges.

By opting for biosourced insulation, you are helping to reduce greenhouse gas emissions linked to the production of traditional petrochemical insulation materials such as expanded polystyrene or even   glass wool . In addition, these materials are also morehealthyfor building occupants because they do not contain harmful chemicals.

In short, biosourced insulation is an ecological solution,economicAndefficientfor the insulation of your building. It allows you to reduce your ecological footprint while improving thecomfortof your habitat.


OTRA, a unique know-how on the Belgian market

OURexpertiseAndexpertisefor more than25 yearsallows you to have what is best on the market in terms of comfort and results ofenergy saving.


At the end of the project, our customers find themselves inhealthy environment, with aexceptional comfortAndsustainable.

THEsolutionsput in place allow our customers to benefit from theprimethe isolation of the region, and the25% surcharge  for the installation of biosourced materials labeled by OTRA. 


THElabeled biosourced materialshave been recognized for theiradded values, therefore there is an additional aid of 25% of the basic amount of the premium for the use of these.

You will also be entitled tofederal aidfor roof insulation for a maximum amount of €3,420/house in 2023

What are your expectations when working with OTRA?  
This is the question we asked our customers. All answer us:


"Living in a comfortable, healthy and economical place".

To meet the needs of our customers, we have set up a strategy specific to OTRA from high-performance solutions in ecological insulation and of finishes to reach thegoals requested.

Take advantage of the ecological and sustainable innovations of the company OTRA

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