A block of flats made of wood in the neighbourhood that will transform Girona

GironaIn Girona, near the border between the neighborhoods of Can Gibert del Pla and Santa Eugènia, there stands a very unique apartment building surrounded by a tree-lined park. It is a building made entirely of wood, with grid-like and symmetrical shapes, a forty-meter facade facing south, and open galleries on each of the six floors. The building, inaugurated in 2022, is called 6x6 and is the work of the Girona-based studio Bosch Capdeferro, which has received numerous awards for the project's sustainability and energy efficiency values.

It consists of 35 identical homes, each 70 m², organized around a rectangular, elongated space without a hallway, with sliding doors that allow for the interchange of uses in each room. All have openings on both sides, and natural light enters all parts of the apartment. This channel structure powers a cross-ventilation system, which in summer captures cooler air from the south facade and distributes it to the north. Then, in winter, on the sunnier north balcony, the glass creates a warm air chamber that helps heat the home. All of this is reinforced by an electric air-to-air heat pump air conditioning system: an efficient technology that extracts energy from the outside air to generate heating, cooling, and domestic hot water.

One of the building's residents is Gemma Estruch, an engineer, who has owned one of the ground-floor apartments for four years. She is delighted: "The concept of it being all open works very well for me. And the wood of the walls, inside and out, gives a very warm feeling, a lot of light comes in, and, moreover, you can't hear anything at all, it's very soundproof," she explains.

"You spend half as much as in a normal flat"

Estruch is very satisfied with the energy efficiency. Although each home behaves differently depending on the height and sun exposure, she assures that it has a direct impact on the bill. "Now, in summer, cross-ventilation helps, although, logically, it doesn't work miracles with the temperatures we have and we have to turn on the air conditioning. Then, in winter, the glass balcony heats the apartments a lot and there are families who hardly turn on the heating. You spend half as much as in a normal apartment," she assures. To generate the natural airflow, each apartment has different ventilation grilles, so you don't have to open the windows to air out or remove bad odors.

There is also a very good atmosphere in the building among the neighbors, especially with those who arrived as soon as the development came onto the market: "There is a lot of community. At first, everyone would grab their beer and we would meet in the gallery, like in the villages before, or the other day, for example, we gathered to celebrate Sant Joan," Estruch continues.

The neighbor arrived at the building without fully knowing the work and the ethical principles of the studio of architects Ramon Bosch and Bet Capdeferro. Once she had the keys, however, as an engineer, she became interested in how the aerothermal system worked and came into contact with the project's ideologues: "At first, as it was all new, we had to solve some problems with the installation of the cold batteries. I met Bet and Ramon and I informed myself a lot. Following this, I prepared a dossier to help new neighbors adjust the basic parameters of the system according to their needs," finishes Gemma Estruch. 

Concrete generates CO₂ and wood stores it

The 6x6 condenses all the philosophy and work of architects Bosch i Capdeferro, always concerned with achieving a harmonious triad between architecture, people, and the environment. "This building has allowed us to culminate and put our convictions into practice. It's not about trying to go against the climate, but about working together with it. Architecture should be a second skin, a second suit, and as such, it must adapt to the changing needs of summer and winter," argues Ramon Bosch.

Furthermore, the two members of the Girona-based studio not only seek to minimize the environmental impact of homes once life begins in them, but also from the embryonic moment of their construction. "The construction sector is responsible for approximately 40% of the planet's greenhouse gas emissions. Therefore, as architects, we have a responsibility to respond to this from the beginning of the process," argues Bosch. And here the choice of wood is fundamental: "Building one cubic meter with concrete generates approximately one ton of CO₂ emissions, while one cubic meter of wood stores one ton of CO₂ captured by the tree during its growth, transformed into cellulose. The difference is enormous," assures the architect. 

However, out of ignorance, building walls and structures of an apartment block with wood might seem unstable or not very resistant. But nothing could be further from the truth: "We are accustomed to trusting buildings made of brick without any brick having undergone a test. In contrast, each cross-laminated timber panel has been tested and certified. It is a very reliable technology. We have the stigma of the Three Little Pigs, but this wood is very resistant. And besides, it retains that almost atavistic quality of living matter, which brings a lot of well-being," argues Bet Capdeferro. And this, ultimately, according to the architects, is the most important thing: "Beyond kilowatt-hour calculations, we want to create memorable, comfortable, and transcendent spaces for people, without ever losing contact with the environment," concludes Capdeferro.

A new public housing development

The 6x6 is the result of a private development driven by a construction company that took a risky bet on this architectural model after the economic crisis. Of the 35 homes, four are officially protected. And the result has been so satisfactory that the public administration wants to continue it. A few meters away, the Girona City Council has launched a new development of 50 officially protected public homes for young people, which will soon be completed. The construction has been awarded to the Bosch Capdeferro studio and the project maintains the same axes of sustainability, efficiency, and wood use. All this in a neighborhood in the southwest of the city that in the coming years will undergo a major transformation based on all the urban development planned around the future new Josep Trueta Health Campus.