Biomaterials in construction in HOLA! magazine

 

Hola! magazine has published a digital article on BIOMATERIALS IN CONSTRUCTION featuring our studio as an expert in sustainable, ecological, and healthy architecture. This Spanish weekly publication has international reach and specialises in topics such as fashion, beauty, and design.

In the article, we discuss the urgent need to use the ‘materials we have always used’ again, such as wood, earth, or plant fibres like straw, and their advantages in creating sustainable, healthy spaces—leaving aside fossil-based materials such as steel, concrete, and plastic, which emit a great deal of carbon.

Biomaterials, as their name suggests, are materials with a low carbon footprint but, in addition, they are biodegradable, natural, healthy, recoverable, reusable, and are key to sustainable architecture. They offer nothing but advantages and are essential to decarbonising the construction sector.

 

 

A simple definition of biomaterials for construction

These materials likely do not need a definition, because they are the materials we have been building with for thousands of years; ultimately, the materials that require fossil fuels are the ones that should carry an adjective. Wood, earth, and straw are materials that are available on Earth with a low or even zero carbon footprint.

Biomaterials can reduce carbon impact to zero and even generate positive impacts on the environment and on people.

Which ones could we describe as ‘fossil materials’? Highly industrialised materials that were introduced into the sector in the last century—such as concrete, steel, and plastics—require energy from fossil fuels to be produced, or else come directly from a fossil fuel, such as oil in the case of plastics.

 

What can I use wood for?

Floors, wall linings, window and door frames, façades, roofs and, above all, structures. It is an exceptional material for constructing tall buildings and can be used in many different ways. Along with plant fibres, it is the only renewable building material.

We still have to fight the myth that a wooden house is not durable and burns easily. Today, timber structures are very well protected against electrical installation faults, which are the main cause of fires. In the event of a fire, studies show that a timber structure withstands heat much better than a steel structure, which collapses sooner.

 

Wood derivatives

Wood also has derivatives, such as cork, wood fibres, and cellulose, which provide the best and most eco-friendly insulation. They offer the advantage of being renewable, widely available, natural, and much more durable than other plastic insulations.

Cork comes with a lifetime guarantee, whereas industrialised plastic insulations such as polystyrene foam may have guarantees of only two years.

 

The quintessential basic material: brick

Brick, made from clay, is the star material in construction. It is another biomaterial, and it should come from a factory that does not use fossil fuels; in that case, its ecological footprint is considerably reduced.

Another application of clay is in roofs, generally pitched, using ceramic tiles. While much less commonly used, another clay-based biomaterial is adobe: it uses clay and sand (mud) as well as straw or other natural fibres as a natural binder.

 

Plant-fibre composites

Hemp, cotton, or wool fibres are mainly used as insulation and have the advantage of being natural in origin, renewable, and free of toxins. In this case, it is important to take the precaution that they must not get wet. The same applies to wood fibres and cellulose.

 

Is there an eco-friendly cement?

The cement production sector is researching how to achieve it, but it does not seem likely to be viable in the short term. Producing this material requires a kiln at temperatures between 1,200–1,500°C, and to reach this temperature today only fossil fuels, such as oil or gas, can be used.

In the case of cement, half of the carbon footprint corresponds to burning fossil fuel and the other half to emissions from the calcination of limestone itself. So, although the industry has very ambitious decarbonisation plans, for the time being they depend on carbon-capture technologies that are not yet developed and, if they are implemented, are expected to double the price of cement.

 

Stone: another material to consider?

Marble, granite, limestone, sandstone, slate… there are many varieties of stone—a biomaterial, although it is not renewable and therefore has a greater ecological impact. In any case, if it is used, it is always better if it comes from a nearby quarry and has a land restoration plan and low water consumption, because stone cutting has that major problem—more so even than transport, the architect explains.

On the other hand, it should be borne in mind that, despite not being a renewable material, stone is respectful of people’s health and is highly durable; as a result, replacement is minimal thanks to its long service life.

You should also consider what protective layer is applied to this porous material, because those that contain volatile toxins (VOCs, short for Volatile Organic Compounds) are harmful.

New-generation materials, such as sintered stone, are alternatives that reduce environmental impact on the territory, but they are not free of carbon emissions in their manufacturing processes either.

 

The time is now!

It is a matter of human survival; our lives depend on it. Scientists warn that if we do not act urgently, the planet will become uninhabitable. Carbon must be reduced to zero by 2050, and steel, concrete, and plastic emit an enormous amount of carbon.

We must work sector by sector, and construction—which is estimated to account for 40% of global emissions—is undoubtedly a key sector in which we need radical, large-scale changes to meet the goals of the Paris Agreement.

To ensure a sustainable future, we must return to biomaterials, which are, ultimately, materials that have been used in the construction sector for several thousand years, but which had been pushed into the background due to the rise of industrialised materials.

 

 

You can read the full article Wood, earth, straw… Returning to biomaterials in construction is urgent! at the following link.