The Hopps Partnership

Adjacent Excavation



In this blog we will look at adjacent excavation, something which often requires a notice to be served upon an Adjoining Owner under section 6 of the Party Wall etc. 1996.

Adjacent Excavation

Adjacent excavation can be any form of excavation however it most commonly applies to digging a foundation for the purposes of forming either a new structure or underpinning an existing one. It can however also include excavation for forming drains or lowering your land for landscaping purposes.

Section 6(1), Excavation Within 3m of an Adjoining Owner:

The first part of section 6 of the Act relates to digging within 3 m of an Adjoining Owner and the below image gives an example of where the Act applies:

In this instance a Building Owner has dug a common strip foundation (a simple strip which is backfilled with concrete) the new structure is not shown, only the foundation in this instance. It can be seen that the neighbour has a relatively shallow foundation with a brick spreader footing. This is very common in Victorian and older properties and it is only relatively recently (in the last 100 years or so) that foundations begun to be formed to deeper levels with the inclusion of concrete although some Victorian properties did include shallow portions of rough concrete.

The new footing where built to building regulation standard is normally at least 1 m deep although can be deeper dependent on the soil conditions and whether there are any trees in the vicinity. The Act is therefore triggered whenever an owner is digging a new foundation which is deeper than their neighbours and is within 3 m. It should be noted that if you are digging within 3 m of any permanent structures next door and to a lower level, you will need to serve the Adjoining Owner with a notice under section 6 (1) of the Act. This therefore includes garden walls, studio buildings where these are of solid construction and not lightweight timber structures and garages among others.

This sort of arrangement with a 1 m deep foundation will be a very common occurrence in modern construction and will generally apply to rear extensions and new build houses where soil conditions are good.

Section 6(2), Excavation Within 6m of an Adjoining Owner:

The second part of section 6 of the Act relates to digging within 6m of an Adjoining Owner however the rule is slightly different and the below image gives an example of when the Act is triggered:

In this instance a Building Owner is installing a very deep foundation, normally what is known as a piled foundation where a deep concrete shaft is sunk into the ground usually necessary for larger construction or where ground conditions are very poor. The act is triggered in this instance when a 45° angle is taken from the midpoint of the underside of the Adjoining Owners foundation, and where this bisects the new foundation and is within 6 m a notice is required under the Act.

We have discussed in an earlier blog what a notice must include in order to be valid however to reiterate, a notice served under section 6 of the act must be accompanied by a plan showing the site and depth of any excavation and a site plan showing the proposed new structure.

Over the years The Hopps Partnership have served this type of notice countless times and we would be happy to assist you with your new work or if you are a neighbour, we can assist and advise accordingly.

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