Zero Net Artificialization

What is soil artificialisation?

A poorly characterized object

According to the French Ministry of Ecological and Solidarity Transition, soil artificialisation corresponds to "any surface area removed from its natural, agricultural or forestry state, whether built-up or not, and whether paved or not". The term therefore refers to a change in land use, i.e. in its economic and social functions, from a natural or agricultural surface to an urbanized surface.

This imprecise definition amounts to considering an urban green space and a built-up area in the same way. This is why ecology professionals supplement it by including both soil quality (structure, composition, biological activity, etc.) and habitat quality (specific richness, plant stratification, ecological functionality, etc.), considering as artificial "environments degraded, damaged or destroyed by human activity". There is therefore not justone kind of artificialization, but several, with different degrees of imperviousness and impacts.

The goal of Zero Net Artificialization (ZAN) and its limits

Soil artificialisation is a major issue of public debate and political concern, especially in France. In fact, in October 2015, soil artificialisation was included in the 10 new wealth indicators established by the Government to monitor its public policies. The following year, in August 2016, the Law for the Reconquest of Biodiversity, Nature and Landscapes was passed, to avoid, reduce and compensate (ERC sequence) for the negative impacts of human activities on the environment. In 2018, the Government's Biodiversity Plan unveiled the goal of " Zero Net Artificialization " (ZAN) by 2030, in order to curb the artificialization of land and the erosion of biodiversity. A 70% reduction in gross artificialization and the renaturation of more than 5,000 hectares would then be required to meet the ZAN.

France Stratégie, at the joint request of the French Ministries of Ecology, Territory and Urban Affairs, was asked to draw up a report to clarify the issues at stake in this objective and propose levers for soil protection. Interministerial and partnership working groups, numerous representatives from the land-use planning sector, NGOs (such as the LPO), and the Convention Citoyenne pour le Climat (Citizens' Climate Convention) have also proposed solutions for moving towards land sobriety.

From the outset, ZAN has been the subject of much debate and criticism, notably for its imprecise definition of land artificialisation, the absence of quantified targets and the use of the term "net", which suggests that the aim is to compensate for rather than eliminate impacts.

 

On a national scale, 47 hectares are built up for every 1,000 inhabitants every year (France Stratégie).

How can we preserve our soil?

To avoid focusing ZAN solely on a restrictive approach, solutions must be multi-disciplinary, multi-actor and realistic. Levers that can be mobilized include :

  • Improving knowledge of the dynamics of soil artificialization.
  • Taxation. Today, it favors urban sprawl, since natural and agricultural land is less expensive than land for building or construction. Renovation also turns out to be more expensive than virgin land for new construction (Comité pour l'économie verte, 2019). It is therefore essential to reform tax incentives to encourage the rehabilitation, reconstruction and optimization of existing buildings (elevation, modularity).
  • Territorial planning integrating the multi-scale challenges of biodiversity protection: ensuring the consistency of territorial planning tools such as PLU(i) and SCoT, right through to local urban planning regulations (thresholds for preserving open-ground spaces at municipal and plot level, biotope coefficients by surface area, soil pollution inventories, etc.).
  • The densification of cities by exploiting land that has already been artificially developed or built-up, while guaranteeing the habitability of these areas.

 

Reviewing our development methods is a priority.

Artificialization in a few figures...

In France, it is estimated that between 16,000 and 61,000 hectares of land are artificialized every year. This discrepancy is due to different analysis methodologies, both in terms of spatial resolution and the nomenclature of land counted as artificial.

In addition to having a higher average level of artificialisation than its European neighbors, France is also experiencing faster growth in artificialised land than its population. According to Teruti-Luca data (annual field survey), artificialized land is estimated to have risen from 3 million hectares in 1980 to 5.1 million today, representing growth of 70%, compared with 19% for population growth over the same period (France Stratégie, 2019).

The growth in land artificialisation is very unevenly distributed across the country, with metropolitan and coastal areas being the main focus. High demand for individual housing and the development of road networks are the two main drivers of land artificialisation.

What are the main consequences of soil artificialization?

The IPBES (The Intergovernmental Science-Policy Platform on Biodiversity and Ecosystem Services), biodiversity's equivalent of the IPCC, estimates that 1 million plant and animal species are threatened with extinction through net habitat loss. France, a true European crossroads on land and sea, is home to around 10% of the world's biodiversity. The Commissariat Général au Développement Durable (CGDD), the Office Français pour la Biodiversité (OFB) and the Observatoire National de la Biodiversité (ONB) estimate that 26% of these species are threatened with extinction or have become extinct as a result of artificialisation.

The destruction and fragmentation of natural habitats and ecological continuities through urban sprawl and urban sprawl are the main causes of this loss of biodiversity. This disrupts species' life cycles, affecting their feeding, migration and reproduction.

Artificial soil is soil where the possibilities for local biodiversity are restricted, and where the quality and quantity of ecosystem services provided by non-artificial soil are no longer guaranteed (carbon storage, air quality regulation, water infiltration, pollination, etc.).

Source : Sinteo

The 6th mass extinction of biodiversity and climate change are realities that are difficult to deny. The result of unchecked human activity on Earth, this environmental crisis is forcing us to rethink all our systems, revolutionizing our ways of thinking and developing.

 

Faced with increasingly stringent regulations and complex procedures, here's some advice

How can we support you in your construction or renovation projects?

  • The choice of land: carry out a study of the regulatory context at all levels of the territory, as well as an assessment of the biodiversity issues of the plot. While it's easy to avoid selecting plots classified as natural, agricultural or forest zones by studying urban planning documents, other parameters may be at risk, such as the presence or distance from a protected or unprotected biodiversity corridor and/or reservoir.
  • The ecological value of the plot: in addition to the context, a study of the plot is essential to avoid any regulatory risk. Unprotected land can be home to locally rare and protected plant and animal species. Architectural and landscaping specifications, for example, can go beyond regulations and restrict operations by setting performance targets. An ecological diagnosis that is proportionate to the issues at stake is therefore essential to secure a building permit, any appeals and controls by the environmental authority.
  • The architectural and landscaping project: thanks to the ecological diagnosis carried out and the resulting choice of target species, the ecologist's recommendations enable the project to be adapted to its context: by limiting the footprint, preserving open ground, creating heterogeneous biotopes that are attractive and function like real ecosystems, all linked to each other. By working with projects from the planning stage onwards, our ecologists can help developers, landowners, architects, landscape architects and design offices achieve biodiversity-positive projects.

Further reflection...

Artificial soils are the result of human activity and the place where people live. Real estate, a high-stakes sector, is therefore one of the levers to change everything. Sinteo is working for post-carbon real estate: doing better with less... By focusing more on renovation and new-build projects in areas that are already artificial.

Aside from the current health context, ZAN remains at the forefront of the debate, prompting us to take a closer look at open spaces as a response to many of the current and future challenges we face. The aim is to work together towards urban requalification, ecological restoration and energy renovation.

Preserving land and, above all, soil biodiversity is essential to creating good ecosystem conditions. Today, active open-ground soil is a rare and precious resource. Revitalizing degraded soil through renaturation work costs a fortune (from €100 to €400/m² excluding deconstruction costs): let's preserve valuable soil!)