Are you selling or buying land to build? If it is located on an area of clay soil, a mushroom-making study will now have to be annexed to the sales agreement. This soil survey must make it possible to detect all the risks of ground movement due to the dryness and re-hydration of the soils, that is to say those related to the removal and swelling of the clays. What operations and areas are involved? What should the study contain? Two orders issued on Official Journal 6 and 15 August 2020 specify this provision provided for in the Elan Act of 23 November 2018.
Clay soils, in case of drought or massive water supply, can gradually weaken buildings, especially the lightest ones such as detached houses. Cracks can then appear and threaten the solidity of the house. The soil survey should enable the buyer to better assess the potential risk and the builder to adapt its construction rules. It must be annexed to the sale agreement with the promise to sell or, in the absence of a promise, to the authentic instrument of sale.
Which operations are involved?
The soil survey concerns:
sales of non-built land suitable for building individual houses (building land);
contracts relating to construction work or project management, in particular contracts for the construction of single-family houses (CCMI).
It does not concern contracts for:
work which does not affect the foundations or structure of the building, the flow of water or the heat exchange between the ground and the basement of the building;
work on extensions, including verandas and garages if the project area is less than 20 m2 and if this new construction is detached from the existing building.
What is in the soil survey?
In the context of unbuilt land, the study of soil
prerequisite
(type G1) must be provided by the seller. This identifies the geotechnical risks of a site and defines general building principles to prevent the risk. It is valid for 30 years. It is intended to help refine risk assessment at the field level.
In carrying out construction work, the contracting authority may:
to provide a geotechnical study of
design
(type G2) taking into account the location and characteristics of the building. It prescribes construction provisions adapted to the nature of the soil, it is valid only for the project for which it was carried out;
or comply with the particular construction techniques defined by regulation.