Planning and regeneration Building over sewers

Requirements for building over sewers

If you are building or extending a building that is within 3m of the centreline of a public sewer the work must meet certain standards to protect both the sewer and the building from any possible damage. In some cases you might need to get formal written consent (A Building Over Agreement) from the sewerage authority (United Utilities) before you start work.

How the sewer can cause damage

Damage to the building or extension may be caused if:

  1. foundations are not suitably designed or constructed and this causes settlement of the ground around the sewer pipe; or
  2. where the sewerage authority need to carry out repairs to the sewer pipe and, in doing so, excavations occur that might undermine the stability of the foundations of the building - causing settlement.

When you need a formal building over agreement

If a building or extension is closer than 3m to the centreline of a sewer pipe and the sewer pipe is more than 225mm in diameter, or the depth of the bottom of the sewer pipe is more than 3m below ground level, you will need to obtain a Building Over Agreement from United Utilities before work begins.

In such cases the protection measures that the sewer authority stipulate in any Building Over Agreement will be inspected by engineers from the sewer authority.

When Manchester Building Control can tell United Utilities that your proposal is adequate

Where a building or extension is within 3m of the centreline of a sewer pipe, and  the pipe is less than or equal to 225mm in diameter, or the bottom of the pipe is less than 3m deep below ground level then Manchester Building  Control has been given authority from United Utilities to approve the  sewer provided the protection measures indicated in the building regulations are followed and the work is inspected by the council's surveyors.

Advantages of the agreement with United Utilities

By working with United Utilities we have reached agreement to avoid their inspectors having to also inspect the drain providing it satisfies building regulations and is within the size/depth limitations referred to above.

Your Building Control Surveyor will be able to advise you further

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