Approved Document C - Site preparation and resistance to contaminants and moisture

This part covers the clearance or treatment of unsuitable material, resistance to contaminants and sub-soil drainage. Information on the resistance of moisture to floors, walls and roofs is included, with examples of damp proofing and ventilation provisions.

Download Approved Document CApproved Document C

PDF file: 2.67MB, 53 pages

2004 edition incorporating 2010 amendments: Valid from 1 October 2010

Download 2013 amendments2013 Amendments

PDF file: 478KB, 54 pages

2013 amendments: Valid from 6 April 2013

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The requirements in this edition of Approved Document C are as follows:

C1 - Preparation of site and resistance to contaminants
(1) The ground to be 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, or to be covered by the building and any land associated with the building.
(3) Adequate sub-soil 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.

Limits on application
None

C2 - Resistance to moisture
The floors, walls and roof of the building shall adequately protect the building and people who use the building from harmful effects caused by:
(a) ground moisture;
(b) precipitation and wind-driven spray;
(c) interstitial and surface condensation; and
(d) spillage of water from or associated with sanitary fittings or fixed appliances.

Limits on application
None

Additional guidance to support Approved Document C

Download Preparing for floodsPreparing for floods

PDF file: 587KB, 100 pages

The information in this document builds on existing planning guidance and also advice on taking extemporary measures to protect against flooding, which is available through the Environment Agency. It contains informed advice that is relevant to the owners of homes and small businesses and people undertaking building work.


Download Better to be safe than sorry! leafletBR 262: Thermal insulation: avoiding risks

The guide discusses the more important technical risks associated with meeting the requirements of building regulations for thermal insulation. Technical risks are highlighted and these are followed by actions that could be taken to avoid the risk. In assessing risks for a particular building, consideration should be given to the environmental conditions likely to occur both inside and outside the building, and its expected life.

Purchase document from www.brebookshop.com


Archived copies of Approved Document C

Download Approved Document C 2006 editionApproved Document C - 2006 edition

PDF file: 1.9MB, 51 pages

Valid from 1 December 2004 until

The requirements in this edition were:
C1 - Preparation of site
C2 - Dangerous and offensive substances
C3 - Subsoil drainage
C4 - Resistance to weather and ground moisture


Download Approved Document C 1992 editionApproved Document C - 1992 edition

PDF file: 5.15MB, 26 pages

Valid from 1 June 1992 until 1 December 2004

The requirements in this edition were:
C1 - Preparation of site
C2 - Dangerous and offensive substances
C3 - Subsoil drainage
C4 - Resistance to weather and ground moisture


Download Approved Document C 1985 editionApproved Document C - 1985 edition

PDF file: 1.65MB, 22 pages

Valid from 11 November 1985 until 1 June 1992

The requirements in this edition were:
C1/2/3 - Site preparation and contaminants
C4 - Resistance to weather and ground moisture


Quick links to other Approved Documents

The regulations cover all aspects of construction and are constantly reviewed. The guidance documents referred to as 'Approved Documents' contain practical ways and explanations of how to comply with the functional requirements of the Building Regulations.

These 'Approved Documents' are separated into 20 parts:

  • Part A - Structure
  • Part B (Volume 1) - Fire safety (Dwellings)
  • Part B (Volume 2) - Fire safety (Buildings other than dwellings)
  • Part C - Site preparation and resistance to contaminants and moisture
  • Part D - Toxic substances
  • Part E - Resistance to the passage of sound
  • Part F - Ventilation
  • Part G - Hygiene
  • Part H - Drainage and waste disposal
  • Part J - Combustion appliances and fuel storage systems
  • Part K - Protection from falling, collision and impact
  • Part L1A - Conservation of fuel and power in new dwellings
  • Part L1B - Conservation of fuel and power in existing dwellings
  • Part L2A - Conservation of fuel and power in new buildings other than dwellings
  • Part L2B - Conservation of fuel and power in existing buildings other than dwellings
  • Part M (Volume 1) - Access to and use of buildings (Dwellings)
  • Part M (Volume 2) - Access to and use of buildings (Buildings other than dwellings)
  • Part P - Electrical safety - Dwellings
  • Part Q - Security - Dwellings
  • Part R - Physical infrastructure for high-speed electronic communications networks
  • Regulation 7 - Materials and workmanship