Any project on natural or agricultural land contributes to the municipality’s “land-sealing budget.” Municipalities favor projects that minimize land-sealing and maximize green spaces. A project with a low land-sealing footprint is more attractive in public land sale tenders.
Paris mandates a green space ratio of 0.3 in certain densely populated areas. Lyon, Bordeaux, and Nantes have followed suit with similar regulations. A green space ratio of 0.3 per 5,000 square meters means that 1,500 square meters must consist of permeable or vegetated surfaces.
| Surface type | Coefficient |
|---|---|
| Natural, unsealed soil | 1,0 |
| Green area in planters or on slabs ≥ 80 cm | 0,7 |
| Extensive green roof | 0,7 |
| Green roof in a container ≥ 30 cm | 0,5 |
| Green facade | 0,5 |
| Permeable pavers with vegetation | 0,3 |
| Waterproof surface (asphalt, concrete) | 0 |
The trend is on the rise.
To optimize the CBS without sacrificing leasable space:
Asphalt-covered surface parking lot = coefficient 0. Underground parking lot with a green roof = coefficient 0.7. The cost difference (underground parking: +€15,000 to €25,000 per space) must be weighed against the regulatory and commercial benefits.
The site plan design must incorporate the following from the outset: green spaces with optimized coverage ratios, landscaped swales for stormwater management, and permeable pathways rather than paved ones.
An extensive green roof costs €50 to €80 per square meter and contributes 0.7 CBS units. For a tower with 1,000 square meters of roof area: a contribution of 700 CBS units.
Using the site plan and the landscaping plan, Netcarbon simulates the project’s environmental status 25 years from now: expected surface temperature, additional carbon stock, CBSh, and effective unpaved area.
For a project comprising 80 housing units with a nature park (3,000 m²), involving the planting of over 691 trees and over 1,151 shrubs:
These figures were included directly in the technical proposal submitted in response to the request for proposals.
Environmental criteria account for 20% to 40% of the overall score in many major cities. The most commonly requested indicators include: overall CBS score, green space area, number of trees, permeability rate, and impact on urban heat islands.
“We will plant many trees” does not carry the same weight as “planting 691 trees results in a reduction of -5.4°C and +52 tCO2 over 25 years, as simulated by Netcarbon.”
The Low Carbon Label (Ville Arborée method) certifies and monetizes carbon sequestration associated with tree plantations. Credits are valued based on the benefits provided by the project and can represent a significant source of funding for the project.
Are you planning a real estate project and looking to optimize your carbon footprint to maximize your chances in green building certifications? Netcarbon can assist you starting from the feasibility phase. Contact our team.
