Within 30 years, summers in Seville will register up to 50 degrees Celsius. The trend in the South of Spain will see heatwaves and droughts increase in frequency, duration, and intensity.

The City Council and the University of Seville partnered to run an urbanisation project for sustainable cities to face these challenges posed by climate change. “Recovering the street life in a climate-changing world” is the slogan and the initiative’s main objective, Cartuja Qanat.

“It is a project whose fundamental objective is cultural, although it has technological and social elements,” says David Pino, Chief Officer of Social Innovation and Social Economy at Seville City Council.

“The challenge is maintaining the culture of ‘living on the streets’ in cities along the Mediterranean when they reach temperatures close to 50 degrees,” he adds.

Towards sustainable urbanisation

During the summer, most of the thermal stress in urban spaces comes from solar radiation. Achieving comfort conditions in the public area depends on strategies such as “blocking the sun without staying in the dark, and subtly controlling the air intake by placing tree screens or diverting the air current as motorcycles do with visors,” explains José Sánchez Ramos, member of the Thermotechnics research group of the University of Seville.

“Once this is achieved, you must blow fresh air where the people are. We’re not talking about air conditioning, but about introducing natural techniques.”

When temperatures are high, objects and surfaces around the audience are expected to be 10 or 15 degrees warmer than the room’s temperature, depending on the material.

“You have to move to the surface treatment: cool it by adding vegetation, sheets of water or with underfloor tubes. In a 45-degree environment, there are possibilities to reduce the temperature to 26-27 degrees playing with all this”, Sánchez Ramos says.

What will the result of this urban transformation be? Streets will be improved and used as social activators. They will also engage the city’s entire ecosystem – public, private and citizens.

In Pino’s words: “The fundamental objective of the project is to generate a test pilot experience of some ancient and other super modern methodology so that friendlier cities will enjoy public spaces that allow us to continue living on the street.”

By applying more than 40 techniques, Cartuja Qanat will be a pioneer in saving energy consumption by using alternatives to air conditioning installations. The expansion of this model throughout the city is expected to gradually change the appearance and functionality of the street concept and its future evolution in the next 15 years.

The amphitheatre, the souk, and the island

The amphitheatre, the souk, and the island are the three main buildings that will occupy the public space. The amphitheatre will use an air cooling technique that employs pond water and Qanats – which gives the name to the project.

“It is called Qanat after the Syrian methodology of the Gobi Desert of 3000 years ago”, says the Chief Officer of Social Innovation.

Sánchez Ramos explains that Servando Álvarez Dominguez, head of the research group, was “the one who studied what a Qanat was, and the technological innovation of the adaptation in Cartuja Qanat is impressive. People will say: ‘I can’t believe what these people have come up with, they’ve tried it, and it turns out it works.”

A channel with water that goes 20 meters deep underground and, through air vents, drives the coolness of the water upwards. That’s what a Qanat is. Below the ground, the water temperature drops 10 to 15 degrees, and above it results in a drop of 6 to 7.

The old souks of Mediterranean cities inspire the style of the second building: the souk. It is located below ground level to minimise outside air entry and exploit shadows, plants, space, and ventilation. The furniture can be tempered, and the grandstands integrate fresh air impulsion systems.

“Nobody has achieved before to lower the average temperature of a public open space from 6 to 10º without using an external energy system”, explains Pino. Until now.

Finally, the tempered island is an open space with vegetation, water elements and furniture. For example, benches made of conventional, heavy, light and thermally activated cement will verify their effectiveness in mitigating the climate.

Replication in the city  

“Part of what we have learned in the process is already applied in other parts of the city,” says the Chief Officer. An example of tempered material is the developed bioclimatic bus shelters placed at a specific temperature. “The stop gives you a ‘thermal hug’, hot in summer and cold in winter”, Sánchez Ramos explains.

But there are also examples of projects related to the water techniques, already designed for school playgrounds, urban squares, new areas with restricted traffic and parks. “The idea is that EMASESA -the municipal public water supply company-, leader of the project, is already incorporating all these techniques when acting in different municipal terms to make a healthier city around water and plant management,” explains Pino.

Not only that, Cartuja Qanat will host an incubator for business projects to facilitate ideas for sustainable models, prioritising those related to air quality, water management, mobility and renewable energies.

A citizen lab

Seville also involves citizens as they propose co-creation workshops to say what they want the spaces to be used. And what happens next? Seville is planning “a permanent citizen innovation laboratory for ideas and debate.

So that people can test, during the next four years, the level of comfort of new spaces, the governance, and what elements to improve. They can also practice how to live together doing different activities in a public space.”

The governance of the future is here, along with climate solutions.