I would like to welcome this network with a written speech on sustainable architecture, natural and raw construction materials, such as straw, hemp, wood etc.  Furthermore, I would like to analyse how the right choices contribute to protecting the health of the tenants as well as maintaining the dwellings themselves. Priority should always be to achieve the users’ comfort without any financial or energy waste.
Have you ever wondered why historical dwellings stand up robustly and remain in good conditions while most modern buildings, under the same climatic conditions, are not as well preserved, made of plasters ready to collapse and with  marks of moisture and mould on walls and ceilings?

The main cause of this lies with the choice of materials that form the wall of a building, the so-called shell/envelope.  It is very important that, both the users of a building and the contractors, are aware of the crucial role materials can play and the fact that a building should be treated as a living organism that breathes, gets sick or dies from suffocation.                                                                                                                                                                      
At this point we should see how the envelope of the house we live in or the building we work in can both guarantee comfort & indoor air quality as well as protect us from external weather conditions. No matter where we live - either in a traditional stone-masonry house, a historical or a modern building - we should quit using concrete-based plasters as these impede transpiration and encourage the formation of humidity and mould on the walls, one of the main causes of asthma, allergies and respiratory infections. We should also quit using acrylic coatings seals which, literally, disrupt the transpiration process and increase the dampness problem. Additionally, VOCs (volatile organic compounds) contained in the organic chemistry’s building materials, worsen the situation of our protective shell and lead to the most "sick" houses.

The fundamental requirement of an owner is that the walls of the building where he spends most of his days are able to breathe and transpire.  Take, for example, the envelope of a conventional construction consisting of bricks: they are porous and actually allow transpiration. The thermal insulation should, therefore, be composed of hypoallergenic materials, without micro powders that are hurtful to lungs, or petroleum derivatives that do not allow walls to transpire but trap moisture and create mould, microorganisms and bad smells. The right insulations, which allow walls to breathe, consist exclusively of fibrous materials such as wood, wool and minerals that deal with the moisture that inevitably exists while still ensuring that the walls remain dry and clean and the indoor air quality equivalent to that achieved with high-quality filters and ionizers.                                                                                                                          
The same approach applies to both plaster and coating to ensure consistency and synergy in transpiration. The plaster must not contain cement trail, which encourages mould formation and impacts on the health of the occupants, leading to respiratory diseases.  Concrete compounds are impervious, watertight and prevent evapotranspiration, while the existence of salts therein is the main cause of fissures in concrete plaster which leads to water intrusion though the walls or through the roof.                                                                                                                                                                                            The plaster should be composed of natural materials, such as natural hydraulic lime NHL, which has the greatest mechanical properties in the history of inorganic chemistry. Natural Hydraulic Lime is a material with high breathability, natural sealing properties and high resistance to fissures due to its elasticity. Consequently, the final finish/coating on the walls will be treated with the same philosophy as every single layer. It is a material that enhances the vapour-permeability & allows moisture to escape. The coatings and finishes that we use, should not be acrylic or silicone (as this creates a suffocating film on the wall surface), but solely Natural Hydraulic Lime or Mineral Silicate Paints, with enhances condensation resistance friendly to the environment and to humans.

Referring to the envelope of buildings and the key role that evapotranspiration plays, I should highlight the decisive role of thermal insulation on the dwellings’ envelope. It should be clear that in the hierarchy of a right and cost-effective construction/renovation of buildings, the envelope is the primary factor to take into account. A shell, thermally reinforced, without thermal losses and thermal bridges, reduces energy cooling/heating demands. Consequently the exorbitant amounts that users pay to utilities (electricity for HVCA) are minimised. Furthermore, a properly insulated building requires smaller electromechanical equipment (burners, boilers, heat pumps, fireplaces, pellet burners, etc.) that significantly contribute to the reduction in operating costs of a residence, office, industrial building, etc.                                                                                                                              It is very important to realise that, both for the domestic economy and the public economy that gets affected by high energy consuming buildings, the long-term expenses and payback time of materials, technologies and plant installations should be taken into account. On this subject, the Life Cycle Assessment of a product, material or technology, which expresses the embodied energy from production up to reuse, is something to evaluate, but not yet in this session.  So I return to the topic of the thermal insulation of buildings to emphasise that a proper shell (walls, windows, roofs, floors) can offer the ideal comfort conditions for occupants/users while reducing energy and operating costs. It is important to note here that consumers spend 80% of their life indoors. 

The aim of creating a harmonious environment that feels 'like home' is a primary task. Security depends on a number of factors and, above all, from our choices!  Along with the security offered by the family, what is important is the space in which we live, the house in which we spend many years of our lives. The beneficial effects on our life and our health are caused both by the physical aspect of the space that we live in and by the use of materials that should be chosen so that they are compatible with one another to create a healthy and quality environment. It happens sometimes that one visits a home or working place which oppress us and make us breathe with difficult. These disturbing impressions are measurable with scientific instruments. It is proven that using natural materials, not harmful for our health or the environment, ensures not only that dwellings provide well-being and safety, but also take into account the economic benefit to users.

The advantages of living or working in a house/building constructed entirely out of wood are many. Wood brings an incomparable comfort to a habitation from which a person gets important vital forces, health and safety. Wooden construction buildings have significant fire and earthquake resistance and the single materials that compose them are certified by appropriate institutions. One of the biggest advantages of wooden buildings, recognised by our customers, is the dual heating and cooling saving benefits, as their envelope consists of solid wood panels. The manufacture duration of a wooden building is such that the time savings are expressed in costs reduction, compared with a conventional construction.

Both in cases of construction or interior renovation of houses and buildings, insulation is a very important factor for the health and economy of tenants/users. As mentioned above, it must be composed of fibrous materials as only these have heat capacity and behave optimally in both warm and cold climates. Thus, the savings are for life, with a significant reduction in PPC accounts or the respective utility company. The air-tightness of buildings is important so as to avoid energy leakages and damages caused by moisture, for both buildings and our health. The natural insulation properties of wood or mineral fibres offer an optimum behaviour in the thermal conductivity of walls while also ensuring the realisation of a mantle lining, impervious to wind and rain, reflecting ultraviolet radiation while allowing the building to breathe.

Glazing and frames play a key role in ensuring the energy efficiency of dwellings. Low-e glazing and thermally broken frames provide important cooling and heating savings. However, equally important to the choice of windows is their installation. A scarce or inadequate installation of frames leads to the creation of thermal bridges thereby reducing the performance of the accurate and expensive windows. There is clearly a specific procedure for windows installation by using appropriate materials and membranes, which promote both transpiration and thermal insulation while blocking the creation of thermal bridges. All this detailed placement and procedure must be certified by experts through energy audits, called Blow Door.

Modern man spends about 80% of his life in a closed environment (home, office, public places or schools) where impurities cause serious respiratory diseases. Mainly in urban centres, the outdoor air pollution from exhaust gases, carbon dioxide, nitrogen oxides and radon, which is found everywhere in the air, makes the natural ventilation by opening windows, completely inadequate to improve indoor air quality. The ideal solution, which can guarantee both comfort and indoor air quality, is the installation of forced ventilation devices either in air-tight spaces such as basements or on the perimeter walls. This type of equipment can filter the air, control the indoor humidity and, through an internal heat exchanger, help maintain the internal temperature without thermal losses.

The materials used to produce plaster, coatings and finishes should be environmentally friendly, without prefabricated concrete or ingredients belonging to the clinker group.
One of the best mortar options are those consisting of calcareous sands, broken grain or natural siliceous sands blended together with natural pure Hydraulic Lime NHL 5, which is produced in temperatures lower  than 1250 ° C by heating silica limestone without adding pozzolanic binders soluble or any other type of material (clinker, cement, fly ashes, blast furnace slag, etc.)
Mineral finishes are waterborne, odourless, non-toxic and VOC free, manufactured with natural ingredients using a low energy manufacturing process. These paints/coatings contain neither solvents nor petrochemical derivatives and do not give off any toxic gases. Over their entire life cycle from raw material extraction to production, the mineral paints and finishes have an excellent environmental profile.