This is how one plant rises per week

In the heart of the Delicias neighborhood, surrounded by brick buildings and next to the Railway Museum, stands Tomás Bretón, the first zero CO2 building in the center of Madrid and one of the first in Spain. Its appearance gives it away: wood is the main material of a different construction, inside and out. There is another element that draws the attention of passers-by: the absence of dust and noise, except for that made by a generator and the rhythmic sound of professional screwdrivers.

Everything is part of an initiative that seeks to reduce costs, deadlines and carbon footprint, led by the construction company Woodea, the architecture studio Satt and the developer Distrito Natural. The latter are also responsible for Entrepatios, a cohousing building built in Usera in 2019 based on the same principles and which already produces more energy than it consumes. In the case of Tomás Bretón, with the 20 homes already sold and built in record time thanks to wood, delivery is scheduled for January 2025.

To achieve their objectives, at Woodea they take advantage of the peculiarities of technical wood, which allows implement methods and systems from other industrial sectors such as automotive. One of the partners and co-founders of this construction company, Pablo Medina, architect and project management specialist, mentions other key elements in the project in conversation with EL ESPAÑOL-Omicrono, such as “industrialization by components, high digitalization and the identification and elimination of waste and waste” to achieve “an ideal combo”.

Wood, material of the future

If the 19th century was that of steel and the 20th was that of glass and concrete, the 21st century is turning the tables towards sustainable construction with less impact on the environment. The latest advances in the production of different types of wood and their great reception by architects from all over the world, Spain included, invite expand its uses and trust it compared to materials such as concrete. Beyond new mixtures and processes, in general its production is more expensive than that of wood, it is not renewable and its carbon footprint combined with that of steel represents more than 10% of global CO2 emissions.

Octavi Uyà, Pablo Saiz and Pablo Medina decided to launch Woodea in 2021 “due to the climate crisis, the housing deficit and its affordability,” explains Medina. By studying what strategies they could use to address these challenges, they discovered that “technical wood could be a great solution, since it is a natural carbon reservoir and allows the application of industrialization concepts to construction”.

This material, which has evolved greatly since the first constructions recorded by archaeologists, offers new possibilities to architects and builders. The most vigorous is CLT (cross-laminated timber), “a highly industrialized product that shapes beams, pillars and panels intended for floors, roofs or wallswhich can reach lengths of up to 18 meters, widths of 3 meters and variable thicknesses starting from approximately 25 mm”, according to a recent report by Mass Madera, a network that brings together experts, companies, institutions and organizations that are pioneers in the use of solid wood in buildings in Spain.

The CLT is the main element of the structure of the Tomás Bretón building, panels that, thanks to digitalization, can be cut with millimeter precision using CNC (control of court numerical), to obtain each piece that is then assembled on site. “Each of the panels has a QR code or an identifier and are loaded in the factory as it is downloaded here,” adds Medina, which allows construction deadlines to be significantly shortened.

The impact of Woodea’s method is direct in cost savings in materials and construction time. In total there are about 14 months, from the beginning of the work to the completion, compared to the 2 years that similar buildings built in concrete usually require. While the three lower concrete floors with four slabs, which correspond to the two basements and the ground floor, have been built in just over 3 months, each of the wooden floors of the structure has only needed between 7 and 10 business days.

“As we work by components, we have a limited number of elements that we can play with. We know that with these components that we have already analyzed and are optimal, we can achieve an economic architecture in times and deadlines“, they explain from Woodea. “It is as if it were a Lego, we have a limited number of components, but that gives us a very interesting agility.”

Another advantage of construction with this method is that it allows for no stockpiles, something that is noticeable in the very clear surroundings of the building, unlike conventional works. “Instead of bringing a lot of material, lowering it from the truck and then positioning it, the loading part of the truck is left here and the tractor head leaves. The material is unloaded in the opposite way to how it has been loaded and The panels are assembled according to the manufacturing sequence directly in each of the sectors”.

Dismantling myths

The most widespread perception is that wood cannot be used as a high-performance structural material, beyond serving for single-family or low-rise homes. Quite the contrary, products such as CLT and advances in structural engineering with wood offer similar strength and stability to steel and concrete. Skyscrapers made of wood are already a reality, as demonstrated by Mjøstårnet, in Norway, and the Ascent MKE Building, in Wisconsin (USA), both almost 90 meters high and 18 and 25 stories high, respectively.

“The resistance of technical wood is similar to that of concrete, but It has 5 times less weightso the impact on foundations is much smaller,” says Medina. Woodea also aims to refute other myths, such as that building with wood is more expensive, something that is disproved when evaluating the total life cycle of the building.

Or the flammable nature of the material, which is prevented thanks to the encapsulation with non-combustible materials or with extra sacrificial layers that protect the structural section in case of fire. “In addition, the capacity of the wood is very predictable in its behavior, it burns at a constant rate, 0.5 millimeters per minute in pine and 0.7 in hardwoods, which allows the necessary evacuation times to be predicted.”

The other big myth around wood construction is that it contributes to deforestation. Quite the contrary, these types of buildings rely on products that guarantee responsible forestry and that reforest to a greater extent than they consume. The wood in Tomás Bretón’s building comes from Galiciaand has the FSC and PFC seals, which certify that it comes from sustainable forests.

“According to Finsa, the main wood producer in Spain, worldwide 44 million cubic meters of wood are produced todaywith 17 million annual growth, but only 10 million are cut,” says Medina. “That remainder of 7 million is not as beneficial as it seems, since it is a firepower in the place of origin, one of the causes along with with climate change, these voracious fires are occurring year after year.

Energy savings

From inside the building, with large windows overlooking the quiet surrounding streets, it is common to see those walking around stopping in front of the wooden structure, which offers a singular contrast with the orange color of the brick buildings that flank it.

However, from the outside it is impossible to detect other characteristics that make it a unique construction. It is a Almost Zero Energy Building (EECN), that is, with very high energy efficiency and designed under the criteria of the low consumption building standard most demanding in the world, the Passivhaus. Great thermal insulation, great airtightness and double-flow mechanical ventilation controlled with heat recovery contribute to this.

That, added to other strategies such as the presence of solar panels on the roof, rainwater recovery or reducing tap flowallows the expenditure on heating, air conditioning and domestic hot water to be minimal, valued together at about 50 euros per month in a 100 m2 home.

The 20 apartments in the building will go from 64 to 146 square meters, with prices starting at 355,900 euros. The building will also have large arcades, a space for coworking or events, an urban garden, a patio and a large shared terrace on the roof. Everything is part of the concept of cohousing, “which promotes the creation of community so that people can have a private life when they want, but also have meeting places and shared experiences in the building and in the neighborhood,” according to the promoter. Natural District.

It is a building destined to mark a before and after, and several developers are already studying the benefits of their strategies in an increasingly regulated context, with a European regulation that came into force in May of this year and poses restrictions on carbon emissions gradual but very demanding.

“It is expected that in 2026 it will enter the Technical Building Code here in Spain and in 2027 analyzes of the life cycle of buildings will begin,” they confirm from Woodea. By 2028, public buildings will have to ensure that they are zero carbon and In 2030 the standard will be extended to all buildings, to reach total decarbonization in 2050. An ambitious objective that is committed to transforming the entire construction sector and will have wood as one of its best allies.