Excavation notices under section 6

An excavation notice is relevant to some digging or foundation work near a neighbouring building or structure under section 6 of the Party Wall etc. Act 1996. This is more specific than merely digging near a boundary. Whether the Act applies depends on distance, relative excavation depth and the neighbouring foundations.

The three-metre test

Section 6(1) can apply where you propose to excavate, or construct foundations, within three metres of a neighbouring owner's building or structure and to a lower level than the bottom of that building's or structure's foundations. Digging within three metres is not, by itself, sufficient: the depth test also matters.

The six-metre test

Section 6(2) can apply within six metres where the proposed works would cut a line drawn downwards at 45 degrees from the bottom of the neighbour's foundations towards your work. You normally need the designer's or engineer's information to assess this properly. Do not guess foundation depths from the age or appearance of a house.

How early should the notice be served?

Give the relevant adjoining owner at least one month's notice before starting qualifying excavation work. The notice must contain the required particulars, including the proposed work and details of the excavation. Section 6 also provides for deemed dissent where the adjoining owner does not give written consent within 14 days; silence is not a green light to commence.

Drawings and information are essential

Unlike many simple notices for works to an existing party wall, section 6 requires plans and sections indicating the depth of the proposed excavations and, where a building or structure is to be erected, its site. The government guidance also says the notice must address whether you intend to underpin or otherwise strengthen or safeguard the neighbouring building's foundations.

Example: foundations for a rear extension

A homeowner proposes an extension with new trench foundations two metres from the neighbouring building. If the trench will be deeper than the neighbour's foundation base, the section 6(1) test may be met. If the depth remains above that base, the three-metre rule is not triggered solely because the houses are close together. The position should be established from technical information rather than assumptions.

What should you prepare before service?

1. A plan showing your property, the adjoining building or structure, and the location of excavation.
2. Sections showing the proposed excavation depth and relevant foundation levels.
3. A description of the foundation or excavation work and intended start date.
4. Any statement required about underpinning, strengthening or safeguarding the neighbour's foundations.
5. The correct details for each adjoining owner affected by the work.

What happens if your neighbour dissents?

A dispute may need to be resolved by the surveyor procedure under section 10. A surveyor can address the rights to carry out the work and relevant safeguards through an award. Separately, planning permission or building regulations approval does not dispense with requirements under the Party Wall Act.

Read our focused explanations of the 3 metre rule, 6 metre rule and notices for extensions.