It seems the unlikeliest of places to promise a future ecological paradise. Barcelona’s Plaça de les Glòries Catalanes has spawned several grandiose plans which ultimately failed to deliver an imagined utopia. The 19th century urban reformer Ildefons Cerdà envisaged it as the city’s cultural heartbeat, but a hundred years later the huge square had evolved into a nondescript wasteland on the industrial outskirts. Flyovers and underpasses then failed to curb chronic traffic problems, while the legacy of the 1992 Olympics was a giant roundabout above a seedy park. By early this century another overhaul was deemed necessary. Today, the site is still a major transport intersection, but much of this is underground. On the surface is a large plaza with plenty of green space and amenities, prioritising not cars but people – and nature.
“It’s no longer a hub for cars, but it’s become a hub for the tram, it’s a hub for people walking, it’s a hub for the bicycle, it’s a hub for everything, but we understood that it could be a hub for biodiversity too,” says Olivier Philippe, co-founder of the landscape architects Agence TER. In 2014 the French firm and its Catalan partner won the contract to redevelop the square. Its “Canopia Urbanà” project remodels the site in three layers: the subsoil, the soil, and in the future some 2,000 trees will grow to form a large canopy. A series of “biodiversity nodes” act as nature refuges, interconnecting to form an urban green corridor. “Today we have 84 species of birds that have been identified. When we started work it was something like 20 species,” Philippe adds. “So, in the centre of a city, in a place that’s crossed by everything – people, cars, public transport, bikes plus an incredible number of underground services – how could this allow such an intense existence of biodiversity? But it seems to work.”
The Barcelona project is among several highlighted by the World Economic Forum in its campaign to integrate cities with nature, while the importance of urban green space and tree canopy cover is recognised in the European Union’s Nature Restoration Law (NRL). Adopted in 2024 against a backdrop of an alarming decline in Europe’s nature – the latest European Environment Agency report found that only 15% of habitats were in good condition, and a third of habitats and species were deteriorating – it sets binding targets to restore degraded ecosystems. The measure was passed despite reticence among several member states – many farmers were fearful of its impact – and after campaigning by international architects’ associations, which highlighted the importance of spatial planning.
Katerina Gkoltsiou, President of IFLA Europe – the European branch of the International Federation of Landscape Architects which welcomed the new law – describes it as “a very efficient tool… to protect and increase biodiversity, to restore natural habitats”. The impact will be “aesthetic… and social – meaning promoting the wellbeing of our citizens and educating the public on the importance of nature, engaging communities in restoration efforts, participation in local conservation projects, and hands-on enhancement of green spaces in cities,” she adds. The IFLA has highlighted several examples of good practice among urban developments – from a vertical forest multi-storey building in Sofia, to a redeveloped dump and landfill area in Helsinki.
In practice, however, the environment sometimes plays a poor second fiddle to other priorities. “For the past two years we’ve had big investors here from all over Europe, developing big hotels and making the territory like a resort. Sometimes we feel we’re becoming like the Algarve, only without the golf! The impact used to be felt in the summertime; now it’s all year round,” says Sofia Branco dos Santos, head of spatial planning in Mafra, just north of Lisbon. The surrounding area is mostly rural and there’s a national park. Increased demand for tourism is putting the coastline under huge pressure. “It‘s private land so it’s difficult for us to meet the challenge over biodiversity or the environment,” she adds.
The Portuguese municipality is one of three districts running pilot programmes under the EU’s BioValue project. Its central aim for spatial planning is to bring about “transformative change” – described as a “fundamental, system-wide reorganisation” – involving players at all levels, from policymakers to developers and members of the public. Mafra has been called on to safeguard and promote biodiversity as one of the Lisbon area’s distinguishing factors, through dialogue with stakeholders. “When decision makers want to change the land use or land occupation, they need to understand ‘if I want to build a resort here, I will lose something else’”, says César Marquês, a senior technician with the project in Mafra who specialises in land use. “That’s our main goal, to provide this information that there isn’t right now. I think when we give this type of information to our decision makers it will influence their decision, because biodiversity and these natural values are part of the quality of living in Mafra. If you don’t have it, we lose this quality of life.”
“We’re saying: ‘if you are going to use a land for development purposes, think first and assess the value that the existing biodiversity can bring to your territory and development, and nourish it’,” argues BioValue’s project coordinator and Professor of Planning, Urbanism and Environment at Lisbon’s University, Maria do Rosário Partidário. She believes green targets can be achieved by focusing on the economic benefits. “The value of biodiversity is reflected in health, in well-being, and in the value of property. Whenever you go to a hotel and you get a sea view, you pay more. Whenever you buy a house that faces a green area, a protected area, it’s worth more; if you have a house that faces an industrial area it loses value,” she says. “There is a value of biodiversity that people don’t want to recognise. Landowners and developers should understand this, but above all spatial planners must prepare for these investments: protect land not because it’s an old area that nobody touches, but because it’s going to improve the value of developed land next to it.”
But is what Maria do Rosário Partidário calls “this positive attitude in relation to biodiversity” enough to encourage good practice? The BioValue coordinator acknowledges that policies are fragmented, that local authorities want investment, and that in times of economic crisis the environment tends to get forgotten. A similar question concerning enforcement can be asked of the EU’s Nature Restoration Law. It says that countries are expected to submit plans by mid-2026 showing how targets will be met, and progress will be monitored.
“The Nature Restoration Law’s adoption should be related to the specificities of the European member states but also to the various types of landscapes and nature. You need to treat differently, for example, a forest in Norway and a forest in Greece,” argues Katerina Gkoltsiou of IFLA Europe. “The NRL gives us a legal framework, but more work is needed now from each country to adjust it to its regulations, socio-cultural context and environment. I believe that any law should not act as a tool used to forbid or punish, but mainly to encourage and reward suitable approaches.”
By the time Barcelona’s “Canopia Urbanà” is complete, it will be almost two centuries since Cerdà first conceived his grand plan. The latest project has been hit by delays and controversy. But for Olivier Philippe of Agence TER, the result will prove that perseverance brings rewards. “Of course, it will take two decades before the tree canopy will be completely efficient. This idea was also about climate change, knowing that in Barcelona like everywhere in Europe and the world, times are getting harder, especially during summer. In Barcelona they’re now envisaging a climate that will be close to today’s Saharan climate – so the tree canopy will indeed bring welcome relief.”
By Alasdair Sandford