Building work that is subject to Building Control under the Building Regulations 2000 (as amended) must have regard to protection of both the building & future occupants from potential adverse effects of the local site / soil characteristics.
Schedule 1 of these Regulations States that:
(Requirement C1.)
(1) The ground covered by the building shall be reasonably free from any material that might damage the building or affect its stability, including vegetable matter, topsoil and pre-existing foundations
(2) Reasonable precautions shall be taken to avoid danger to health and safety caused by contaminants on or in the ground covered by the building and any land associated with the building.
(3) Adequate subsoil drainage shall be provided if it is needed to avoid:
(a) the passage of ground moisture to the interior of the building:
(b) damage to the building, including damage through the transport of water-borne contaminants to the foundations of the building
(4) For the purpose of this requirement, ‘contaminant’ means any substance which is or may become harmful to persons or buildings including substances which are corrosive, explosive, flammable, radioactive or toxic.
Approved Document C sets out how these requirements should be addressed in the building control process; containing the recommendations for making sure your property remains watertight (free from damp penetration & condensation) and protected from any contamination that may be in the ground.
It should be noted that if contaminating substances in the ground have the potential to attack building materials it may lead to a breach of Part A of these Regulations which relate to structural safety.
The requirements of the regulations apply whether or you need to make a full plans application, or are undertaking works under a building notice. The approval of works undertaken is carried out by approved Building Control personnel, which may include either local authority technical officers, or certified private inspectors.
General information about building regulations is available on the Planning Portal Website, and the full text of Approved Document C is available here >> (adobe acrobat *.pdf reader required: links to external site)