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Frequently Asked Questions


We gathered the most frequently asked questions concerning our philosophy, the benefits of our products and our technical solutions. Can't find the answer to your question, or need more details? Send us a message and consult our online library. 

General Questions

General questions

What are you calling 

a bio-composite?


A bio-composite is a mix made out of bio-sourced components.

Our ingredients grow without stressing nature and are processed without chemicals or additives.

What are you calling a "healthy interior"?


A healthy interior is defined by:


  • Stable indoor temperature

  • Stable humidity level around 50%-60%

  • Toxic-free air

  • Alkaline atmosphere

  • Comfortable noise control

  • Low CO2 level

What the difference between Hemp and Cannabis?


Hemp is a variety of Cannabis called Cannabis Sativa. It doesn't contain THC, the psychotropic molecule. The use of Cannabis Sativa is very old. As early as 2000 BC, Chinese used it for its fibers and nutritious seeds. It grows without the need of phytosanitary products, preserving the earth field. A standard hemp house needs 2 acres of hemp cultivation (average).

What is HES-Mix and how do I build with it?


HES-Mix is HempLime and made directly on the building site, using HES products and mixing machine. Only the necessary quantity is produced, without waste. Once the mix is ready, it is poured in a formwork, by hand, to build and insulate walls, roofs, floors or attic. Electrical and plumbing elements are usually installed before casting the HES-Mix.

Why should I use natural materials?


For thousands of years we have built our houses from what nature offers us. From ice and snow to bamboo. Many of those building are still there after hundreds of years.


All our ancestors did was good for nature and good for humans. Then some 80 years ago man invented synthetic building material most of which derived from petrol or minerals. The motivation was money and time without any regards for nature and the health and our well-being.


We are now correcting this, by first of all showing that nature is perfectly able to supply us with building materials and that with that we can build once more houses and buildings that will last for hundreds of years and be to the good of nature and humans.

But why hemp and lime as basic materials ?


Hemp, namely the Cannabis Sativa plant, without toxic elements, has been in the service of man for more than 4000 years in most civilizations.

Used for clothing, paper and many other purposes (rope was the main use for hemp fiber) it grew all over the world. 25 years ago we discovered that the stem of the plant contained a large amount of silica (sand) which prevented it from burning or rotting. Thus an ideal building material.

What can HempLime do that other modern materials can't?


Note firstly that HempLime (HES-Mix) is a living product, not a dead as synthetic products. It is because of its continuous action, called “carbonation”, able to deliver the best thermal insulation. Because of its combination of hemp and lime it regulates worst cases of humidity, even in bathrooms, without ventilation.

It cannot burn, and that without fire-retardants. It does not rot, because of the silica. It will last for hundreds of years in a building and thereby assure a long life investment for the owner. It does not contain any trace of toxic materials and finally it can be re-cycled and return as such into nature.


The main difference is the Hygrothermal behaviour. HES-Mix regulates temperature and humidity inside the buildings whatever are the outside variations. The benefits are comfort and energy savings. It works as well during winter or summer.

How expensive is your system compared to current products?


The cost of products delivered on the building site is comparing well with current products. But we have to take the total cost, material and labour in comparison. In renovation the total cost will be close to equal. On new-buildings the cost of products are again about the same, but the application, thanks to the simplicity and fastness, HES-Mix system comes in less expensive than current systems.

As example a new-building of 125 m2 with 25 cm HES-mix under roof, 35 cm HES-Mix as walls plus finishes inside and outside and floor insulation of 20 cm will amount to a material cost of € 20-22 000 euros.


Using HES-Mix also allows to save on heating and ventilation as the HES-Mix and HES-Wall auto-regulate temperatures and humidity. 

Building with HES-mix

Building with HES-mix

Can I build a whole house with HES-Mix?


HES-Mix can be used everywhere to build walls, floors and attics, once the structure of the building is ready. HES-Mix is not load-bearing material, but constitutes a wall and insulation in one. As it dries, it becomes extremely hard and resistant.

What kind of structure for the house you recommend?


We recommend to use wood or steel for the overall structure and HES-Mix for the rest. See our documentation for comprehensive informations about the possibilities.

How is HES-Mix applied, do you use bricks of HES-Mix?


We do not make pre-molded bricks for now. HES-Mix is made directly on site and applied using a formwork. Our goal is to limit C02 emission during all the process, from the hemp crops to the finished walls. All ingredients are directly shipped to the construction site from our local warehouse.

Can I use HES-Mix on existing concrete or stone walls?


Yes, HES-Mix is perfect for insulate existing walls, floor or attiques. It can be directly applied on almost every kind of existing material. The thickness of the insulation with HES-Mix depends on the existing solutions, but we even used it on Venitian Palace, to prevent salty water to degrade existing structure.

Immediate benefits

Why is HES-Mix an outstanding insulation material?


Several different parameters make HES-Mix a perfect insulation material. Hemp hurds are naturally porous at a macro and micro levels and capable of absorbing and dissipating humidity without rottning, due to the high level of silica. See the certifications and documentation to know more technical details.

Why is HES-Mix a outstanding humidity controller material?


Certified tests have proven that HES-Mix is capable of fast and efficient temperature control without using air conditioning, even in the most extreme conditions (sudden rise or decrease in outside temperature). This is due mainly to the inner structure of the hemp, that is full of air bubbles at macro and micro levels.

HES-Mix is made out of a dried plant, should I worry about fire?


We have a european certification that proves what we already knew: HES-Mix does not burn and exhaust no toxic smoke. This is due to the lime and the high degree of Silica in the hemp. It's like trying to burn sand and the certification gave us the same grade as concrete.

What is an alkaline interior?


Hydrated lime and minerals reacts with water to absorbs CO2. This makes your interior less acid and more alkaline. In today traditionally isolated houses, the air is polluted with petrol derivated materials, exhausting many toxics and acid particles in the air. Many studies show that acid interior are responsible for the growth of disease such as asthma.

Environmental & health benefits

Is HES-Mix recycable?


Yes, HES-Mix is 100% recycable. After demolition, it can simply be re-introduce in the nature, to lower cultivated fields acidity for example

How can HES-Mix absorbs CO2?


One of the component of HES-Mix is hydrated lime (pure Calcium Carbonate). This element naturally reacts with water (humidity), capturing CO2 and keeping it inside it molecular structure. For a house of 120 m2, two floors, using an average of 100 m3 of HES-Mix, 10 t of CO2 will be captured (source: INRA 2005). Imagine if all our houses do the same!

Can HES-Mix used in warm/cold countries?


Yes, HES-Mix, due to its inner capillary structure, compressed water vapour (humidity), resulting in a 'tempered' walls effect, thus participating in a pleasant feeling. In warm countries, the same phenomenon provides a natural, passive, air conditioning, saving energy and money.

What are the waste when building with HES-Mix?


There is no waste. We produce directly on-site the necessary quantity of HES-Mix for your building. We limit the transport to the minimum necessary with our network of affiliates.

Differences with other materials

What's the difference between HES-Mix and traditional concrete?


HES-Mix constitutes a wall and insulation all-in-one whereas concrete needs to be covered with a multi-layered insulation protection.

For the same price as concrete, HES-Mix gives your interior a healthy alkaline and perfectly isolated atmosphere, that absorbs CO2 and is 100% natural.

What's the difference between HES-Mix and straw?


HES-Mix is much more solid, is fire-proof without extra additives and is a better insulation material. 100% natural and 100% recyclable, it is also a CE certified bio-composite for building long-lasting, sustainable houses.

What's the difference between HES-Mix and bricks?


Bricks, like concrete, come from a process that emits huge quantities of CO2. It needs heavy industrial facilities to produce. Hemp comes directly from the Nature, without heavy processing. As soon as lime is mixed with hemp and water, it starts absorbing CO2.

What's the difference between HES-Mix and hempcrete?


Traditional hempcrete use cement or hydraulic lime. Cement comes from a heavy CO2 industry and does not keep your interior healthy because it's a "dead" material. Hydrated lime has the disadvantage to take longer to dry, increasing the cost of building and therefore cannot be convenient for all kind of construction.

Comparison: synthetic insulation materials vs HES-Mix​

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