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What we do…

We are active in the following business sectors:
Heritage - Tertiary - Individual & collective housing


In a few numbers :

+ 15,000 m2 of lime-hemp

+ 7.000 m2 cork

+ 59,000 m2 of insulation in natural fibers, hemp, grass fibers, rice straw, straw, wood ...

+ 35,000 m2 of natural plasters applied: clay, lime, plaster / lime, natural plaster

+ 3,550 tons of CO2 captured / saved in 9 years

OTRA is very active in the construction and renovation sector with bio-sourced and ecological materials, with a low carbon footprint.


OTRA's strength lies in the mastery of the techniques for installing these natural materials and the resulting beneficial effects.


In construction, we offer different construction systems:
- the ideal single-wall insulating system for a contemporary style. Concrete or steel frame and natural insulation

- the scalable post-beam or log and half-log system, with an insulating envelope, charm and authenticity await you

In renovation, we optimize comfort and aesthetics thanks to our:

- insulation from the outside ITE

- ITI interior insulation


Exterior finishes and interior decoration:

- Hydraulic or aerial lime techniques,

- Clay and rammed earth techniques

- Cladding, brick / stone slabs, bricks, recovery slabs

- Custom natural plasters

The materials we use also have recognized technical and energy advantages :

- Excellent thermodynamic or active capillary capacity

- Natural management of water vapor migration. Eliminates the risk of damage to the building structure

- Proven acoustic performance

- Excellent inertia allowing phase shift and felt interior comfort

- Fire resistance class according to standards

- Diffusivity of materials and radiation of their accumulated heat for better comfort, even at lower temperatures


From a climate point of view, they offer a positive carbon footprint

From an ethical point of view, they allow a rational use of local resources or from the circular economy.


For Otra, the preferred materials are hemp, lime, clay, earth, wood fiber, natural plaster, cork, straw, natural plasters ...


Beyond the performances, the materials we use have incredible aesthetic qualities making each project a unique work of timeless design.


We always try to have a coherent approach that combines charm and authenticity in a healthy environment.


We want each of our achievements to be imbued with emotions, feelings and comforts.

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